CXCR2 and infection: Furthermore, the higher expression of chemokine (CXC motif) receptor 2 (Cxcr2), Fc gamma receptor III [Fcgr3 (Cd16)], and ferritin heavy chain (Fth1) in clusters 0, 1, 2, 4, and 5 indicated the presence of migrating and maturing neutrophils, regardless of infection status (Figure 5D).