ERT2 is an alias for the gene, Mitogen-activated protein kinase 3, in humans. Other names include: MAP kinase 3; MAPK 3; Extracellular signal-regulated kinase 1; ERK-1; Insulin-stimulated MAP2 kinase; MAP kinase isoform p44; p44-MAPK; Microtubule-associated protein 2 kinase; p44-ERK1; ERK1; HS44KDAP; HUMKER1A; P44ERK1; P44MAPK; PRKM3. The encoded protein is an enzyme with an amino acid length of 379 and a mass of 43.1 kDa. ERT2 is a member of the Protein kinase superfamily, CMGC Ser/Thr protein kinase family, MAP kinase subfamily. This gene shares homology with other species, including: Mouse, Rat.