Expression analysis of HNF4α in a castration-resistant prostate cancer (CRPC) xenograft model VCaP-CRPC showed that HNF4α displayed a significant decreased expression in castration-relapse VCaP-CRPC xenograft tumors as compared with precastrated VCaP xenograft tumors (Supplementary Fig. S1c). The gene discussed is HNF4A; the disease is prostate cancer.