What are 'checkpoint' immunotherapy drugs? | Immunotherapy | Cancer Research UK

This video explains the concept of so-called 'checkpoint' immunotherapy drugs (also called checkpoint blockers, or checkpoint inhibitors), which work by allowing a patient's immune system to target their cancer.

0:01 What are checkpoint immunotherapies?
0:29 Infected cells and molecules
0:38 Immune cells and how they help
0:51 Cancer makes things more complicated
1:06 PDL1 - what is it?

Our immune cells protect us from harm, patrolling our blood in search of potential problems, and travelling to sites of infection or damage. These cells need to spot the difference between health and unhealthy tissues. For example, when our cells are infected with virus, they need to be destroyed. Infected cells display different molecules on their surface from healthy cells, indicating they’re damaged. Immune cells can recognise these signs of disease and pass on instructions that tell the infected cell to self-destruct. But when it comes to cancer, this situation is a lot more complicated. For a tumour to grow it needs to avoid detection. One way tumours can do this is to produce molecules that can trick the immune system .One of these is called PD-L1. It interacts with a molecule on the immune cell, telling it to ignore the cancer. But researchers have now developed drugs to interfere with this process, allowing the immune system to attack the cancer. And for some cancers, these new immunotherapies look set to change the way the disease is treated.

[nirsamra]

but PD1 cousing the t cell to go throw aproctosise proces no ? not to igonre the cancer