FOLH1 and infection: To verify whether R-405 could cause a bona fide infection of PSMA-positive human prostate tumor cells, PSMA-positive LNCaP cells derived from human androgen-dependent prostate adenocarcinoma lymph node metastasis [48], and PSMA-positive 22Rv1 cells, a human prostate carcinoma epithelial cell line [49] were selected.