There are a number of ELISA Kits available for the measurement of Ribosomal Protein S6 kinase, 90kDa, polypeptide 1, another term for the human protein, ribosomal protein S6 kinase A1. Other synonyms may include: ribosomal protein S6 kinase alpha-1, 90 kDa ribosomal protein S6 kinase 1, MAP kinase-activated protein kinase 1a, MAPK-activated protein kinase 1a, MAPKAPK-1a, RSK-1, and S6K-alpha 1. It is encoded by the RPS6KA1 gene to yield a protein 735 amino acids in length and 82.7 kDa in size. However, there are up to 4 reported isoforms. The protein, an enzyme, is categorized into the Protein kinase superfamily, AGC Ser/Thr protein kinase family, S6 kinase subfamily. Versions of Ribosomal Protein S6 kinase, 90kDa, polypeptide 1 are present in other organisms, including: Mouse, Rat, Frog, Chicken.