Classification of normal RPTs into high (strong staining) and low (weak/absence staining) levels of HCaRG showed a significant difference in tumor diameter (P = 0.0362), pathological T stage (P = 0.0041), Fuhrman grade (P = 0.0085) and recurrence within 5 years (P = 0.0296). The gene discussed is COMMD5; the disease is neoplasm.