CXCR2 and chronic kidney disease: Neutrophils expressed high levels of Cd44, Il1b, Cxcl2, Cxcr2, Mmp9, and Ptgs2 mRNA, suggesting that they contribute to nonresolving renal inflammation during AKI-to-CKD transition (Figure 6B, Supplemental Figure 11, and Supplemental Data File 2).