# Inhibitor

Source: https://onco.cc/terms/inhibitor/  
OnCo record `inhibitor` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A drug that blocks a specific protein from doing its job, usually by lodging in the pocket the protein needs to work. Most targeted cancer drugs are named after what they inhibit.

## Summary

Inhibitors can bind reversibly (competing with the natural substrate) or irreversibly (forming a permanent bond, as afatinib does with EGFR), and can bind the active site or a separate pocket that distorts the protein (allosteric inhibition, as sotorasib does with KRAS G12C). The name usually tells you the target: PARP inhibitor, CDK4/6 inhibitor, checkpoint inhibitor, aromatase inhibitor. Because inhibitors only block rather than remove a protein, the cell can escape by making more of it, mutating the pocket, or rerouting the signal; degraders, which destroy the protein, are one answer.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: inhibitors; inhibits; inhibited; inhibition; inhibiting; blocker; blockers; blockade; small-molecule inhibitor; small-molecule inhibitors; small molecule inhibitor; small molecule inhibitors

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Enzyme_inhibitor
- Wikipedia: https://en.wikipedia.org/wiki/Enzyme_inhibitor

## Connected records

- terms: [Agonist and antagonist](https://onco.cc/terms/agonist-antagonist/), [Drug resistance (primary and acquired)](https://onco.cc/terms/resistance/), [Enzyme](https://onco.cc/terms/enzyme/), [Kinase](https://onco.cc/terms/kinase/), [Targeted therapy](https://onco.cc/terms/targeted-therapy-term/)
- technologies: [CDK4/6 inhibitors](https://onco.cc/technologies/cdk46-inhibitor/), [KRAS & RAS inhibitors](https://onco.cc/technologies/kras-inhibitors/), [PARP inhibitors](https://onco.cc/technologies/parp-inhibitor/), [PROTACs & molecular glues (targeted protein degradation)](https://onco.cc/technologies/protac-degrader/), [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/)
- drugs: [Olaparib](https://onco.cc/drugs/olaparib/), [Palbociclib](https://onco.cc/drugs/palbociclib/), [Sotorasib](https://onco.cc/drugs/sotorasib/)

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JSON: https://onco.cc/api/v1/entities/inhibitor.json