According to the extent of difference between cryptorchidism and normal testis, the expression of seven downregulated genes (PLCZ1, AKAP4, AKAP3, IZUMO1, SPAG6, CAPZA3, and ROPN1L) were further selected for validation by qPCR (Figure 7). The gene discussed is IZUMO1; the disease is cryptorchidism.