Moreover, elevated CXCL9 concentrations could distinguish SARS-CoV-2-associated multisystem inflammatory syndrome in children from other hyperinflammatory syndromes like Kawasaki disease and macrophage activation syndrome, underlining the potential of CXCL9 as a predictive marker in COVID-19 disease progression.27 The gene discussed is CXCL9; the disease is COVID-19.