Nuclear receptor coactivator that can enhance preferentially estrogen receptors ESR1 and ESR2 transactivation. Also modulates progesterone/PGR, glucocorticoid/NR3C1 and androgen/AR receptors transactivation, although at lower level; little effect on vitamin D receptor/VDR. Required for normal spermiogenesis. It probably plays a role in acrosome formation (By similarity). . This is the function of CCDC62 (coiled-coil domain containing 62, ENSG00000130783).