SLC22A1 and prostate cancer: To further elucidate the biological meaning of this SNP in prostate cancer, we focused on its regulatory mechanisms affecting SLC22A3 expression for two reasons: (1) among the two genes (SLC22A1 and SLC22A3) influenced by this SNP, SLC22A3 exhibits relatively high transcription expression (Supplementary Figure S2); (2) functionally, SLC22A3 has been reported to be related to drug efficacy [15,19].