Expression of HDACs in high-grade PIN was almost identical with the strength of expression in the corresponding invasive carcinomas (HDAC1: r=0.961, P<0.001, HDAC2: r=0.756, P<0.001, HDAC3: r=0.694, P<0.001), indicating that HDAC overexpression is an early event in prostate carcinogenesis. The gene discussed is HDAC9; the disease is invasive carcinoma.