In a recent phase III multicenter clinical trial of corifollitropin alfa in azoospermic men with hypogonadotropic hypogonadism, it was demonstrated that administration of 150 μg of a long-acting FSH preparation given every second week leads to significant increase of testicular volume and induction of spermatogenesis, comparable to the effects seen with short-acting recombinant FSH preparations (25). This evidence concerns the gene BRD2 and hypogonadotropic hypogonadism.