Immunotherapy as a boon in cancer treatment

Abstract Immunotherapy is considered as one of the emerging tools for the treatment of cancer. Immunotherapy deals with the manipulation of our immune system to kill cancerous cells. Components of innate and adaptive immunity play vital roles in the recognition and killing of cancer cells. Among these components, CD8+ cytotoxic T lymphocytes (CTLs) are the most important to kill cancerous cells. There are various costimulatory and coinhibitory checkpoints that stimulate or inhibit immunogenic signaling against cancer. Targeting these checkpoints has revolutionized cancer treatment. However, there are multiple hurdles which need to be overcome to make it successful as chemotherapy, radiotherapy, and surgery. Currently most of the cancer immunotherapeutic agents are under clinical trials. This chapter summarizes the mechanism of modulation of various stimulatory and inhibitory checkpoints, drugs under trails, and the limitations of cancer immunotherapy.