CLDN1 and atopic eczema: Indeed, emerging evidence suggests that clinically unaffected skin barrier properties in atopic dermatitis are compromised, as decreased levels of claudins-1, -4, and -23 have been found in nonlesional skin, and an inverse relationship between claudin-1 and Th2-polarized responses has been observed (De Benedetto et al., 2011; Brandner et al., 2015).