**4.1 The immune checkpoints and inhibitors**

Immune checkpoints help regulate immune responses and prevent overactive immune responses.

One type of immunotherapy is checkpoint inhibition, which targets immune checkpoint molecules to release the brakes on the immune system and enhance its ability to attack cancer cells. ICIs have shown promising results in preclinical studies and is being actively investigated as a potential treatment for cancer.

Checkpoint inhibition is currently a highly active area of research in the field of cancer treatment, with the aim of developing effective immunotherapies that can help improve patient outcomes and provide new treatment options for cancer patients. Following are some examples of the phagocytic immune checkpoint axes that has been targeted to treat various types of cancers.
