MAPK3 and neoplasm: The application of the MEK inhibitor trametinib thus could attenuate PF‐induced ERK1/2 phosphorylation in DLD‐1 and HCT116 cells (Figure S7, Supporting Information), and we wondered whether the combination of PF (DKC1 inhibitor) and trametinib (MEK inhibitor) could synergistically suppress tumor growth.