Comparable to the HF ORS, the cultured ORS keratinocytes showed a stratified structure and were positive for TJ proteins Cldn-1, Cldn-4, Ocln and ZO-1 in protein specific localization patterns: Cldn-1 was the most widespread and Ocln was restricted to the uppermost viable layer where all TJ proteins were present (Fig. 3a–d,a′–d′) and which was positive for K75, denoting a CL (Fig. 3j,j′; compare to Fig. 2 and15 for localization of TJ proteins in human anagen HF). Here, CLDN4 is linked to hydrops fetalis.