ACE2 and hydrops fetalis: As we could detect a specific and definable expression pattern of ACE2 and TMPRSS2 in cross and longitudinal sections of HF specimens as well as in various layers of the multilayered, keratinized squamous epithelium of the skin, we next analysed the expression of the host entry factors in isolated, primary keratinocytes, which are the predominant cell type in the hair organ.