HSD3B1 and hypospadias: DIHP down-regulates the expression of many key genes in testosterone synthesis (Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, and Hsd17b3), which leads to a decrease in the synthesis of testosterone, and the expression of Insl3 that leads to the reduction of INSL3, resulting in developmental defects in the male reproductive tract, such as cryptorchidism and hypospadias.