CTLA4 and cancer: Previous findings connecting oncogenic RAS activation with increased PD‐L1 levels in vitro and in vivo suggests potential benefits of combining targeted therapy using a small molecule inhibitor of RAS with immunotherapy using immune checkpoint inhibitors or monoclonal antibody blockade of PD‐1, CTLA‐4, B7‐H3, and PD‐L1 thereby blocking the immune checkpoint activity of cancer cells and increasing the anticancer activity of immune cells, especially T‐cells.23, 35, 36, 73, 74, 75, 76, 77