Similarly, removal of Tnfr1 only minimally delays the observed lethal dermatitis induced by loss of receptor-interacting serine/threonine-protein kinase 1 (Ripk1) or FAS-associated death domain protein (Fadd) in epidermal keratinocytes (Ripk1E-KO or FaddE-KO)10–12. Here, FADD is linked to dermatitis.