MAPK1 and cancer: Interestingly, a recent report identifies suppression of STING signaling via mutant p53 binding and inhibition of TBK1 downstream of STING in breast cancer cells, suggesting that STING-mediated interferon responses may be prevented in p53 mutant cancer cells via this mechanism.32 In contrast, higher rates of mutation in PI3K and MAPK1 were observed in pnSTINGhigh signature cases.