To date, experimental HF regeneration has been attempted mainly by co-transplantation of KCs and trichogenic DP cells into an in vivo environment represented by the intracorporeal spaces of immunodeficient mice (Weinberg et al., 1993; Zheng et al., 2005; Ehama et al., 2007; Kobayashi et al., 2010). Here, TBCE is linked to hydrops fetalis.