Most children presenting with PIMS-TS fulfilled the criteria of macrophage activation syndrome (MAS) in the study conducted by Verdoni et al. Leukopenia, thrombocytopenia and elevation of the biomarkers of inflammation (IL-6, procalcitonin, CRP, ferritin and D-dimer) and, hypoalbuminemia are frequently reported in children presenting with PIMS-TS. This evidence concerns the gene IL6 and Timothy syndrome.