KRT5 and hydrops fetalis: Their hair growth was macroscopically normal during early HF organogenesis (p1‐p12) (Fig. S2A, B) and up to the first anagen (p29), comparable to control (Mcl‐1f/f or Mcl‐1f/+) and K5‐Cre/Mcl‐1f/+ littermates (Fig. 2A, B).