Testicular tissue samples were collected in population of 84 control boys aged 0 to 16 years classified into 7 group according to age and compared between two situations of pathology linked to androgens: 1/ premature secretion of testosterone in childhood in case of Leydig cell tumor (LCT); and 2/ defect of androgen receptors (AR) in complete androgen insensitivity syndrome (CAIS). The gene discussed is AR; the disease is Leydig cell tumor.