SELL and familial Mediterranean fever: Of note, one heterozygous FMF patient with persisting symptoms (one to two attacks per month despite regular colchicine intake, patient 2.13 in Table S1) demonstrated a rapid shedding of CD62L comparable to the effects observed in homozygous FMF patients and different from heterozygous healthy mutation carriers (gMFI 18.5%), indicating a possible link to disease activity beyond genotype effects.