CXCL2 and flatulence: Based on the above data, it was of interest to determine whether IL-1 signaling is essential for optimal production of the neutrophil chemokines CXCL1 and CXCL2 after GAS or S. aureus challenge and, therefore, whether IL-1R-deficient mice would display reduced neutrophil recruitment at sites of GAS or S. aureus infection.