IL1A and macrophage activation syndrome: Presently, inhibition of IL-1α/β signalling with recombinant IL-1Ra (anakinra), together with corticosteroids, has proven useful in the clinical treatment of MAS (Miettunen et al., 2011; Bruck et al., 2011; Ajeganova et al., 2020; Phadke et al., 2021; Naymagon, 2022; reviewed by Mehta et al., 2020a; Gleeson et al., 2022).