We compared the gene expression profiles of castration-resistant prostate cancer and androgen-dependent prostate cancer, and obtained 23 overexpressed ligand-encoded genes and 39 overexpressed receptor-encoded genes from the castration-resistant PCa, such as FZD5, BMP6, TNFSF10 (TRAIL), etc. The calculation procedure was shown in S1 Fig. The gene discussed is FZD5; the disease is prostate cancer.