Fig. 1. The ERK MAPK signaling pathway. Kinases mediating ERK MAPK signaling are sequentially activated by phosphorylation. ERK1/2 are terminal kinases in MAPK signaling that can translocate to the nucleus to regulate transcription programs mediating growth/migration/differentiation. Aberrant activation of ERK signaling through RAS and RAF mutations is observed in >30% of human cancers and extensive drug discovery efforts have been directed towards this pathway for targeted cancer therapies. However, reactivation of ERK signaling with RAF and MEK inhibitors has prompted interest in targeting ERK1/2 directly. Percentages reflect the TCGA provisional data sets accessed via cBioPortal (; http://www.cbioportal.org/).
