GLI1 and cancer: HH/GLI1 signaling regulates immune checkpoint modulators such as PD1, CTLA-4, TIM3, LAG3, TIGIT, and IL-10 in exhausted T cells as well as PD-L1/2, CD80/86, OX40L, CD137L, IDO, and CCL22 in cancer cells [95,114,117,118].