A much weaker, but still significant difference in DRB*11 frequency was also observed between boys with bilateral cryptorchidism and controls (pcorrected = 0.037, O.R. = 3.000), whereas patients with unilateral cryptorchidism were not different from control in frequency of any HLA-DRB1 or -DQB1 allele tested (Table 4). This evidence concerns the gene HLA-DRB1 and cryptorchidism.