Transforming growth factor beta (TGF-beta) is a multi-functional cytokine that plays a fundamental role during embryonic development and tissue homeostasis in metazoans. Changes in TGF-beta signalling are implicated in prostate cancer (PCa) and benign prostatic hyperplasia (BPH), two of the most common diseases affecting ageing males. GAGEC1 belongs to the GAGE-related family of cancer/testis associated antigens and in males is expressed only in prostate and testis. Previous reports demonstrate that GAGEC1 is up-regulated in symptomatic BPH and PCa. We demonstrate GAGEC1 up-regulation by TGF-beta1 in primary prostatic stromal and epithelial cells. Our data suggest that disease-associated increases in TGF-beta1 may account for the increase in GAGEC1 expression in BPH and PCa. Given its restricted spatial expression in males, GAGEC1 represents a promising target for therapeutic intervention of BPH and PCa.