Additionally, we also found that 4SC-202 upregulates expression of MICA and ULBP1, which encode ligands for an activating receptor—NKG2D, expressed on natural killer (NK) cells—and stimulate the NK cell-mediated cytotoxicity against cancer cells, indicating that 4SC-202 may provide favorable immune-modulatory effects on cancer treatment (Figure 8G) [77,133]. Here, KLRK1 is linked to cancer.