But published data about COL4A5, which encodes for one of the six subunits of type IV collagen that is a major component of the basement membrane, are in accordance with a potential tumor suppressing function: type IV collagen was shown to be reduced in the basement membrane of prostate tumors (85) and loss of COL4A5 was particularly noted in invasive prostate carcinomas (86). The gene discussed is COL4A5; the disease is prostate neoplasm.