In the reported case, the presence of high gonadotropin levels (not consistent with central hypogonadism typical of true hyperprolactinemia), the absence of a pituitary adenoma, the difference in PRL values measured by the different employed analyzers and the patient’s job (butcher), led us to suspect the presence of anti-animal antibodies. This evidence concerns the gene PRL and hypogonadotropic hypogonadism.