Other members of the STAMP family include pHyde, a rat protein that has been implicated in the apoptosis of prostate cancer cells (6), and its human homolog, tumor suppressor-activated pathway 6 (TSAP6), also known as STEAP3, a p53-inducible gene, involved in apoptosis and the cell cycle in prostate cancer and HeLa cells (7). Here, TTLL5 is linked to prostate cancer.