Serine/threonine-protein phosphatase 6 catalytic subunit (PP6C A) is the catalytic subunit of protein phospatase 6 (PP6). PP6 is a component of a signaling pathway regulating cell cycle progression in response to IL2 receptor stimulation. The N-terminal domain of PP6C A restricts G1 to S phase progression in cancer cells, in part through control of cyclin D1. PP6C A downregulates MAP3K7 kinase activation of the IL1 signaling pathway by dephosphorylation of MAP3K7. PP6C A is ubiquitously expressed in all tissues tested with highest expression levels in testis, heart, kidney, brain, stomach, liver and skeletal muscle and lowest in placenta, lung colon and spleen.