While the keratin 15+ve bulge is considered the primary HF SC niche, housing “the most quiescent and long‐lived” population of cells 5, more recently identified SC populations also exist within the HF, such as the Lgr6 and MTS24 positive isthmus region 7, 8, and the Lrig1+ve junctional zone 9. Here, KRT15 is linked to hydrops fetalis.