ERCC1 and Azoospermia: Finally, preclinical data showed that a mice model lackingthe ERCC1 gene (an important DNA repair gene) developed both azoospermia andcancer.54 Strengtheningthis hypothesis is the well-known association between cryptorchidism, testicular cancer, andaltered semen parameters with data showing a strong association between delayed orchiopexyand an increased rate of cancer/infertility, thus clearly suggesting the key role of“in situ environmental factors.”52