CFTR and cystic fibrosis: Consistent with this, some studies have shown that CFTR pathogenic variants may also cause other non-CBAVD Azoospermia (Chen et al., 2012; Dohle, 2002; Smits et al., 2019), in addition, phenotypic heterogeneity of CF patients with N1303K variant could be explained by the presence of specific haplotypes (Cordovado et al., 2012; Osborne et al., 1992).