BPIFA1 and hypohidrotic ectodermal dysplasia: Other examples include the BpifA1 mutant, in which the loss of the antimicrobial/surfactant protein product SPLUNC1 impairs auditory tube function (Bartlett et al., 2015), and the hypohidrotic ectodermal dysplasia (HED) mutants IkBαΔN, EdardlJ/dlJ, EdaTa/Y and EdaTa/Ta, in which the nasal and nasopharyngeal glands and their products are absent (Schmidt-Ullrich et al., 2001; Azar et al., 2016).