CALCOCO1 (calcium-binding and coiled-coil domain-containing protein 1), also known as cocoa, calphoglin, sarcoma antigen NY-SAR-3 or coiled-coil coactivator protein, is a 691 amino acid protein that shuttles between the cytoplasm and nucleus and functions as coactivator for aryl hydrocarbon and nuclear receptors. A member of the CALCOCO family, CALCOCO1 is forms a calphoglin complex with PPA1 and PGM 1 and contains multiple functional domains through which it acts as a component of both the androgen signaling pathway and the Wnt/β-catenin signaling pathway. CALCOCO1 exists as three alternatively spliced isoforms (termed Q9P1Z2-1, 2 and 3), which are encoded by genes mapping to human chromosome 12q13.13 and mouse chromosome 15 F3.