CTAK1, or MAP/microtubule affinity-regulating kinase 3, is a human gene encoded by MARK3. It may also be known as: C-TAK1; cTAK1; Cdc25C-associated protein kinase 1; ELKL motif kinase 2; EMK-2; Protein kinase STK10; Ser/Thr protein kinase PAR-1; Par-1a; Serine/threonine-protein kinase p78; MAP/microtubule affinity-regulating kinase 3 ; KP78; PAR1A. The encoded protein is an enzyme with an amino acid length of 753 and a mass of 84.5 kDa. Other isoforms may exist. CTAK1 is a member of the Protein kinase superfamily, CAMK Ser/Thr protein kinase family, SNF1 subfamily. Homologs of this gene exist in other organisms, including: Frog.