As FLG is an important skin barrier protein and mutations of the human FLG gene are associated with ichthyosis vulgaris and atopic dermatitis36,37, we investigated FLG-interacting proteins in the manatee, which has retained FLG, and the dugong, which has lost the C-terminal portion of FLG (Fig. 5A,B). Here, FLG is linked to inherited ichthyosis.