MAPK1 and neoplasm: Oncogenic KRAS promotes pancreatic tumorigenesis through the activation of multiple downstream pathways, including RAF/MEK/ERK, MAPK, PI3K/Akt, Bad, and nuclear factor κB (NF-κB).41, 42 Inhibition of KRAS and its downstream pathways has been shown to reduce tumor growth and enhance gemcitabine chemotherapeutic efficacy against pancreatic cancer.43, 44 Downstream effectors of KRAS signaling in pancreatic cancer have been widely explored.