TNFRSF1A and TNF receptor 1-associated periodic fever syndrome: The processing enzyme(s) responsible for TNFR1 cleavage is still undefined, but TNFR1 cleavage is obviously an important step in the regulation of cellular TNF-α responsiveness, as cleavage-resistant TNFR1 mutations are linked with dominantly inherited autoinflammatory syndromes (TNFR1-associated periodic syndromes, TRAPS).