Figure 6.

Model for the regulation of major histocompatibility complex class I (MHC‐I) expression in non–small cell lung cancer cells by epidermal growth factor receptor (EGFR)‐MEK‐extracellular signal‐regulated kinase (ERK) signaling. Mutational activation of EGFR leads to down‐regulation of MHC‐I expression through the MEK‐ERK signaling pathway. EGFR‐tyrosine kinase inhibitors and the MEK inhibitor trametinib increase MHC‐I expression via inhibition of ERK activation. The increase in MHC‐I expression facilitates recognition of the cancer cells by intratumoral T cells and thereby promotes an antitumor immune response