Cortes et al. compared inhibin B and FSH serum levels with testicular parameters obtained through testicular biopsy in children with bilateral cryptorchidism: all subjects showed low concentrations of spermatogonia and gonocytes at biopsy, nearly 24% also had low levels of inhibin B and 9% of boys with both these parameters also had increased FSH, while a decreased level of FSH was found in about 5%, compared to normal ranges for age. The gene discussed is BRD2; the disease is cryptorchidism.