POMC and neoplasm: Men with CAH have low fertility rates compared with the normal population, and this is related to testicular adrenal rest tumors (TART).1,2 Development of the primitive adrenal cortex occurs close to the gonads and TART is considered to be an aberrant adrenal tissue that has descended with the testes.3 Pretumor development and growth of these cells is assumed to be adrenocorticotrophic hormone (ACTH) dependent, and undertreatment may play an important role in tumor development.