CXCL2 and bacterial pneumonia: CXCL2 is canonically a potent chemoattractant in bacterial pneumonia (Adams et al., 2021), but its role has not been well-studied with Spn. One study showed that the administration of the proinflammatory cytokine IL-12 could improve innate defense in the lung against Spn by inducing IFN-γ production, enhancing CXCL2 expression, and thereby increasing neutrophil recruitment to the lung after infection (Sun et al., 2007).