TNF and TNF receptor 1-associated periodic fever syndrome: Even in a heterozygous state, TRAPS TNFR1-mutant cells exhibit both spontaneous and sustained LPS-induced MAPK activation, resulting in heightened cytokine production, including TNF, IL-6 and IL-1β.100 How IL-1β is activated in TRAPS patients remains unclear, yet like TNF inhibition, IL-1 blockade is also used therapeutically.