KRT15 and hydrops fetalis: HF markers, such as Keratin 15 (KRT15), Keratin 17 (KRT17) and Keratin 24 (KRT24)47–49, as well as the well-known HF stem cell marker CD3443,50 were specifically localised to the oeHFs in oeSKIN samples, supporting the notion of an active oesophageal-to-skin cell fate switch taking place.