MAPK3 and cancer: In humans, melanoma-associated fibroblasts inhibit the proliferation and function of melanoma-specific cytotoxic T cells through IL-1.54 Previous studies have shown that combined MEK inhibition and antibody-mediated PD-1/PD-L1 blockade sensitizes RAS/RAF-mutant cancer cells to apoptosis.55,56 Our study clearly demonstrates that ERK1/2 activation induces IL-1β expression in BCCs and osteoblasts.