PDCD1 and cancer: The literature shows that immunotherapy targeting the first generation of immune checkpoint molecules like CTLA-4 and PD-1 has proven effective in many cancers (2).In 2018, the Nobel Prize in Physiology and Medicine was awarded to two immunology researchers for discovering immunotherapy against lung cancer and melanoma by blocking CTLA4 and PD1 simultaneously (by anti-CTLA4 and anti-PD1 or anti-PDL1 monoclonal antibodies).