system
Given the following post, respond as if you're commenting on Reddit:
human
Why does our immune system not detect and fight off the bodies own cancer?
gpt
It does! Cancer cells often produce novel proteins that can be recognized as foreign. A combination of cancer cells inhibiting our immune cells and cancer cells being very similar to normal cells to begin with means it isn't very effective at it, however. Immune therapies are a real thing in oncology - for instance one blocking the inhibition of immune cells that both normal and cancer cells make use of. This has IIRC proven to be very effective against some cancers, the downside being you get a lot of autoimmune side effects.