ERK2 is a 42 kD dual specificity kinase also known as mitogen activated protein kinase 1, extracellular signal regulated kinase 2, MAPK1, and p41mapk. The MAPK family includes several subgroups encompassing the ERK, JNK, and p38 kinases. ERK is phosphorylated in response to various extracellular signals inducing homodimerization and nuclear translocation where it phosphorylates target proteins regulating cell growth and survival. ERK2 interacts with a number of proteins including STAT5A, estrogen receptor alpha, ELK1, MEK1, protein kinase c epilson, RAF1, ribosomal S6 kinase, VAV1, STAT5b, Shc and many others. The Poly6242 antibody recognizes human, mouse, and rat ERK2 and has been shown to be useful for Western blotting, immunoprecipitation, and immunohistochemistry.