STEAP1 and Familial prostate cancer: Machlenkin et al. (2005) identified two novel immunogenic peptides derived from overexpressed prostate antigens, prostatic acid phosphatase (PAP) and STEAP1, and found that they could induce peptide-specific CTLs targeting human leukocyte antigen-A2.1+ LNCaP cells to inhibit tumor growth in adoptive immunotherapy, providing great potential as candidate vaccines for patients with prostate cancers.