STEAP2 (Six-Transmembrane Epithelial Antigen of the Prostate 2), also known as STAMP1, PCANAP1, IPCA1, or PUMPCn, is a member of the STEAP family of metalloreductases. It is highly expressed in the prostate, with lower expression in the heart, brain, kidney, and pancreas. In cancer, STEAP2 is significantly upregulated in prostate cancer, including metastatic and hormone-refractory forms, making it a promising tumor-associated antigen for targeted therapy. Drug development has progressed to clinical trials, with AZD0516, an antibody-drug conjugate (ADC) targeting STEAP2, currently being evaluated for prostate cancer treatment.