Reversible inhibition of TGFβ signalling in TGFβ3-expressing cells (HF lineages and epidermal suprabasal cells) of mouse skin leads to HF defects, together with aberrant epithelial differentiation in the upper HF, resulting in infundibular cysts expressing IVL and FLG and containing Oil Red O-stained lipids. The gene discussed is TGFB1; the disease is hydrops fetalis.