Somewhere in your body, right now, a cell is going wrong.

I'm not trying to scare you. This is just an average Thursday. Your cells copy themselves billions of times a day, and copying is a messy business. Mistakes creep in. Most get caught. A patrol of immune cells wanders your tissues doing the biological equivalent of checking IDs, and when it finds a cell wearing the wrong molecular face, it kills it on the spot. You win this fight every day of your life without noticing, the way you never notice the fires that don't start.

The scale of that is stranger than you'd think. Right now, today, you are almost certainly carrying more than a hundred precancerous lesions in your pancreas alone. Some people carry over a thousand. Almost none of them will ever become anything, and until this year nobody could properly explain why a very small number do. I read that figure a few months ago and had to put the paper down for a minute. We are all walking around riddled with the beginnings of it, all the time, and the overwhelming majority of us will die of something else entirely.

Cancer is what it looks like when one of those bad cells slips the patrol. An inside job. A cell that was you, that is still mostly you, that has learned to walk past the guards wearing a face they've been trained not to question.

For fifty years, our entire strategy against that has been to wait.

We waited for the rogue cell to become a lump. We waited for the lump to become a diagnosis. And then, on the far side of that diagnosis, we fought like hell with poisons and radiation and increasingly clever drugs, and we got extraordinarily good at it. Five-year survival for the most common cancers has roughly doubled in my lifetime. That is one of the great underreported wins of the human race, and I will die on the hill of saying so.

But look at the shape of it. Everything we built happened after the line. After the phone call. After the moment that splits a life cleanly into before and after, the moment I spent a chunk of my twenties studying up close.

I did my PhD teaching machines to read cancer out of raw DNA, hunting for the typos in the code that tell you a cell has gone bad. You sit with that data long enough and you stop seeing tumours and start seeing text. Cancer stops being a monster and becomes a spelling mistake that learned to spread. Beautiful, in the way only something trying to kill you can be. And the whole time, the frustration underneath the work was always the same. We were forensic scientists. We showed up after the break-in, dusted for prints, and did brilliant work identifying a burglar who was already inside the house.

This year, in journals almost nobody outside the field reads, that started to change. We've begun handing the guards the mugshot before the break-in.

Let me show you three of them.

In January, a team at MD Anderson led by Eduardo Vilar-Sanchez published results in Nature Medicine for a vaccine called NOUS-209. They gave it to people with Lynch syndrome, a hereditary condition that stacks the deck so badly that cancer isn't so much a risk as an appointment; many carriers will face it by midlife. The vaccine doesn't treat a tumour. There often isn't one yet. It shows the immune system a set of molecular faces that Lynch cancers tend to wear, so the patrol learns them in advance. Forty-five people. Early days. But the T cells woke up, learned the mugshots, and a year on the researchers were seeing fewer precancerous lesions and no new advanced polyps. The body was catching the thing before it became the thing.

Hold your excitement at exactly the right temperature here, because I have to. This is a phase 1b/2 safety trial, not a victory parade. It shows the immune system responding, not lives definitively saved. But something real has moved.

Then there's melanoma, and this is where the argument stops being a hope and turns into a result.

Moderna and Merck built a vaccine called intismeran autogene that gets read off your specific tumour, a bespoke wanted poster printed from the mutations unique to you, and gave it alongside standard immunotherapy to people who'd already had a melanoma removed. The question was whether it could stop the thing coming back. Five-year data from the mid-stage trial landed this year: the combination cut the risk of recurrence or death by 49% compared to the drug alone. Five years out, 68.8% of the people who got the vaccine were still clear, against 49.1% of those on the drug alone. Cut the odds of the after having an after. Nearly in half.

And then, in August, the big trial reported. Eleven hundred and thirty-seven patients. It hit its main target and the big secondary one, cutting both recurrence and the spread of the disease to distant organs. That makes it the first time in history that a personalised cancer vaccine has succeeded in a phase 3 trial, and the first time any mRNA cancer therapy has.

I'd underline that sentence if I were you. Phase 3 is the one that goes to regulators. Everything before it is a conversation between scientists; this is the part where a thing becomes a medicine.

And the third one is my favourite, because of its sheer nerve. A vaccine called LungVax, built by Sarah Blagden at Oxford and Mariam Jamal-Hanjani at UCL, running on the same platform half the world got in the arm during COVID. The first trial starts this year, and it's deliberately small: a handful of people right at the top of the risk curve. Some have already been treated for early lung cancer and are living with the knowledge that it comes back more often than not. Others were picked up through NHS lung health checks. They get a jab designed to teach the immune system the earliest cellular signatures of a disease most of them haven't got. If it works, the next phases widen to thousands.

Fewer than one in ten people diagnosed with lung cancer survive it for a decade. That number has barely shifted in my lifetime. LungVax is the first serious test of an idea that sounds absurd until it doesn't: vaccinating against a cancer the way we vaccinate against a virus.

Except we've already done it once, and almost nobody noticed. The HPV vaccine has cut cervical cancer risk by close to 90% in women in their twenties who got the jab at twelve or thirteen. A cancer that killed hundreds of thousands of women a year is being quietly dismantled in the generation currently in their twenties. No parade. No headline. Just a slow, enormous subtraction happening in the background of everyone's life.

Notice what's happening across all three. We are no longer only asking "how do we defeat this tumour?" We're asking "how do we make sure it never gets a foothold?" Eric Topol, one of the sharpest readers of medicine alive, has been calling this the shift toward interception, and interception is exactly the right word. It's the difference between the ambulance at the bottom of the cliff and the fence at the top. Between the fire brigade and the smoke detector. We are learning to treat cancer the way we already treat heart disease: not as a verdict handed down on a single terrible afternoon, but as a probability you can push down, year after year, before it ever becomes a story you have to tell your family.

I want to be honest about the sting in this, because a good news story that skips the caveat is just advertising. Melanoma is the one that's proved itself; the other two are still early, small, and narrow, and some trials like them will fail, because that's how the real work goes. The melanoma vaccine is also a bespoke product, printed from one person's tumour, which means cold chains and specialist centres and a price tag nobody has published yet. Even the things that work will land first with the people who have the money, the specialists and the postcode to reach them. The gap between what medicine can do and what most people can access is about to get wider before it gets narrower. That gap is the real fight of the next decade, and it won't be won in a lab.

But step back and look at the trend under the noise. For a century we fought cancer as an enemy that had already arrived. We are starting, cell by cell, trial by unglamorous trial, to fight it as an enemy we can turn away at the door.

The most important morning of your medical life might now be one where nothing happens. No lump, no phone call, no line drawn through your years. Just a cell going wrong somewhere in the dark, and a patrol handed its photograph in advance, making sure you never find out how close it came.

How do you feel grateful for a catastrophe that never introduces itself?

That frustration I mentioned earlier, the forensic scientist showing up after the break-in, is more or less why I do the work I do now. Most organisations treat technological change exactly the way medicine treated cancer for fifty years: wait for the lump, then fight like hell. I spend my working life making the case for the other posture, in keynotes and workshops for leadership teams and conferences who'd rather see the thing coming than react to it. My book, Full Stack Human, is the long version of that argument. If it's the argument your team is having right now, have a look at what I do or just reply to this email and let's find a date.

Stay human. The world needs it.

— Tāne Hunter
Founder, Future Crunch
Co-author, Full Stack Human

P.S. There's a small irony I keep chewing on. The thing that makes these vaccines possible is the same thing that makes cancer so hard. Every tumour is a unique misspelling of you. For decades that uniqueness was the enemy, the reason nothing worked for everyone. Now it's the addressee. We finally got good enough at reading the individual typo that we can print a wanted poster with just one face on it. The cancer's own signature became the thing that gives it away. Somewhere in that there's a lesson about the parts of ourselves we're most ashamed of, but I'll let you write that one.