In conclusion, our study on Sex Cord Stromal Tumors in childhood showed a possible switch to embryonal gonadal phenotype: respectively, juvenile granulosa cell tumors appeared to express a FOG-2/GATA-4 pattern in keeping with primordial ovarian follicles and Sertoli-Leydig cell tumors with embryonal testis. The gene discussed is GATA4; the disease is Leydig cell tumor.