Importantly, the luminal A like subtype showed signs of luminal cell differentiation and secretory activity (monitored for example by tumor cell PSA synthesis) and low cell proliferation, a phenotype similar to that of the normal prostate epithelium, while the luminal B-like showed signs of luminal cell dedifferentiation, low PSA expression, and high cell cycle activity [6, 7]. Here, KLK3 is linked to neoplasm.