Steroid receptor coactivator 3 (SRC3) belongs to the SRC family of proteins that interacts with nuclear receptors to facilitate transcription. The 3 homologous members of this family are SRC-1 (NCoA-1), SRC-2 (GRIP1, TIF2, or NcoA-2), and SRC-3 (p/CIP, RAC3, ACTR, AIB1, or TRAM-1). SRC3 is an oncogene that is reported to be amplified and/or overexpressed in breast and gastric cancer and stimulates AKT signaling and cell growth and tumorigenesis.