TNFRSF9 and COVID-19–associated multisystem inflammatory syndrome in children: Regarding the clinical manifestations of MIS-C, Reiter et al. with the use of a PEA (Target 96 Inflammation and Cardiovascular III panels of the Olink platform), observed that the decreased serum levels of certain proteins [TNF-related subfamily member 9 (TNFRSF9) and apoptosis-inducing ligand (TRAIL)] were associated with cardiovascular manifestations and myocarditis in children with MIS-C [5].