CXCL9 and isolated hyperferritinemia: Children with hyperferritinemia > 500 ng / mL had higher levels of C-reactive protein, sCD163, IL-22, IL-18, IL-18 binding protein, MIG/CXCL9, IL-1β, IL-6, IL-8, Il-10, IL-17A, IFN-γ, IP10/CXCL10, MCP-1/CCL2, MIP-1α, MIP-1β, TNF, MCP-3, IL-2RA, IL-16, M-CSF, and SCF; lower ADAMTS13 activity, sFasL levels, whole blood ex vivo TNF response to endotoxin, and TRAIL levels (P-value < 0.05) (Fig. 2, Additional file 1: eTable 1, eFigure 3); and more Adenovirus, BK virus, and multiple virus DNAemias (P-value < 0.05) (Table 2, Fig. 1).