Enhances the androgen receptor transcriptional activity in prostate cancer cells. Ligand-independent coactivator of the peroxisome proliferator-activated receptor (PPAR) gamma. Interacts with the androgen receptor and the retinoid X receptor (RXR) in a ligand-dependent manner. Additional isoforms seem to exist. Widely expressed. Also detected in adipose tissues and in different cell lines. Isoform Beta is only expressed in testis. A chromosomal aberration involving NCOA4 is found in papillary thyroid carcinomas (PTCs). Inversion inv(10)(q11.2;q11.2) generates the RET/NCOA4 (PTC3) oncogene.