IFNG and lymphadenitis: Previous studies have shown that CD64 on PMN is induced by cytokines, such as G-CSF and IFN-gamma [32], while a high CD64 expression on PMN has been reported in patients with acute and chronic inflammatory conditions, such as bacterial infections, sepsis, and autoinflammatory disorders, including Familial Mediterranean Fever (FMF) and PFAPA (Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis) syndrome [30, 31, 33, 34].