Autoimmunity
Because of their role as regulators of inflammation, constitutive activation of certain CARD proteins, either conferred by mutation or by constant presence of stress signals, has been suggested to play a causative role in a number of inflammatory syndromes. Gain-of-function mutations in the intracellular NOD2 protein has been linked to increased risk for Crohn's disease. Activating mutations in at least two related PYD-containing proteins, cryopyrin/CIAS-1 and pyrin/MEFV, have been linked to Muckle-Wells Syndrome and familial Mediterranean fever, respectively.
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