CXCL9 and streptococcal pharyngitis: The three CXC chemokines CXCL9, 10, and 11 are closely related, act through the same receptor (CXCR3), are expressed in the context of streptococcal pharyngitis, are antibacterial towards S. pyogenes[31], and are induced by the cell wall-anchored M protein from S. pyogenes[32].