In 2000, Douglas Hanahan and Robert Weinberg published a paper asking a deceptively simple question: what do all cancers have in common?
Not in terms of where they appear or what organ they affect — but biologically. What capabilities does a normal cell have to acquire before it becomes cancer?
Their answer became one of the most cited papers in scientific history.
The framework
Cancer is not one disease. It is dozens of diseases that share a common playbook. The Hallmarks are that playbook — a set of functional capabilities that cells systematically acquire on the path from normal to malignant.
The original six hallmarks were published in 2000. Two updates followed: in 2011 (adding two hallmarks and two enabling characteristics) and in 2022 (adding four more emerging hallmarks). The current framework has 14 total.
Definition(Hallmarks of Cancer)
A set of functional capabilities that cells acquire during tumor development, enabling them to grow, survive, invade, and spread. First described by Hanahan and Weinberg (2000), updated in 2011 and 2022.
Why it matters
Before this framework, cancer biology was a collection of disconnected observations. Individual genes, individual pathways, individual tumors. The hallmarks gave the field a shared vocabulary and a way to organize everything that had been discovered.
Every targeted cancer therapy is an attempt to block one of these hallmarks. Every post in this series is an attempt to understand one of them more precisely.
The 14 hallmarks
| # | Hallmark | Added |
|---|---|---|
| 1 | Sustaining proliferative signaling | 2000 |
| 2 | Evading growth suppressors | 2000 |
| 3 | Resisting cell death | 2000 |
| 4 | Enabling replicative immortality | 2000 |
| 5 | Inducing angiogenesis | 2000 |
| 6 | Activating invasion and metastasis | 2000 |
| 7 | Reprogramming cellular metabolism | 2011 |
| 8 | Avoiding immune destruction | 2011 |
| 9 | Genome instability and mutation (enabling) | 2011 |
| 10 | Tumor-promoting inflammation (enabling) | 2011 |
| 11 | Unlocking phenotypic plasticity | 2022 |
| 12 | Nonmutational epigenetic reprogramming | 2022 |
| 13 | Polymorphic microbiomes | 2022 |
| 14 | Senescent cells | 2022 |
Each post in this series covers one hallmark — what it is, how it works, and what studying it actually looks like in a lab.
Note
Posts #07, #08, and #12 connect directly to research I worked on. The metabolic paper (HDAC6 inhibition) sits in hallmark #07. The three immune evasion papers (Atf7ip, TSC1/TSC2, Nemvaleukin) are all variations on hallmark #08. The KMT2D paper is hallmark #12 made concrete.
What's next
The series starts with the original six hallmarks from the 2000 paper — the ones Hanahan and Weinberg considered essential. First up is sustaining proliferative signaling: how a cell learns to grow without being told to, and why that single capability is the entry point for almost everything else.
Summary(Summary)
Cancer is not random chaos — it is a structured acquisition of capabilities. The Hallmarks framework distills a century of biology into 14 functional traits shared by every malignant cell. Understanding each hallmark is understanding one piece of the machinery that turns a normal cell into something dangerous. This series covers all 14, with a focus on the ones that connect directly to experimental research.