In the testis, high local physiological levels of the ACE2 enzyme, which have been reported to grow in the testicles of infertile men [161], could play a protective role, by acting in two ways (Figure 4): (i) by lowering AngII(1−8) levels and reducing its signalling through the AT1 receptor and (ii) by generating Ang-(1−7), thus activating the Mas receptor-dependent pathway and limiting the damaging effects of precursor accumulation AngI and AngII. This evidence concerns the gene ACE2 and Infertility.