MAPK1 and cancer: Therefore, aberrant activation of MAPK signaling may prevent the death of cancer cells from drug treatment.54 Numerous studies have confirmed that MAPK signaling is involved in drug resistance induced by various chemotherapy drugs such as gemcitabine, platinum, 5‐fluorouracil, and tamoxifen.55, 56, 57, 58 Ercan et al59 revealed the amplification of MAPK1 gene in EGFR kinase inhibitor‐resistant NSCLC cell lines.