Question: what have you found out about cancer cells that don't respond to immunotherapy

Jamie Honeychurch answered on 29 Oct 2025:

This is a great question. The immune system needs to be able to “see” the cancer cells in order to kill them. Often cancer cells will hide from the immune system. Do you know much about T cells and how they work? They need to see an “antigen” which looks different to the normal body and this usually means that it is a pathogen so they attack it. They also need to see “antigen” expressed by cancer cells. So cancer cells that dont respond to immunotherapy often don’t express antigen or only very low levels of antigen. They may also stop immune cells being able to get to the tumour cells or surround themselves with other cells that stop the killer immune cells working properly. Finally they may stop expressing the molecules that the immunotherapy is targeting. It is very complex and there are lots of different ways they can escape the immune system. That’s why it is so hard to develop treatments that work for everyone.