SOAT1 and Infertility: However, how these two proteins interact remains unexplained. A recent functional study showed that SLC26A3 another anion exchanger expressed in the genital tract is able to activate CFTR by attaching itself via its STAT domain to the R domain of CFTR (Fig. 5). This activation is suppressed by a missense mutation in the STAT domain, the frequency of which is significantly increased in infertile men of Finnish origin (Wedenoja et al. 2017). In addition, in male SLC26A3−/− mice, fertility is reduced mainly due to severe disorganization of epididymal cytoarchitecture (El Khouri et al. 2018).