CXCR2 and neutropenia: In our study, pharmacologically induced CXCR2 LOF in mice displayed pathogenic phenotypes similar to those described in patients with germline CXCR2 LOF variants, such as peripheral blood neutropenia, accumulation of mature neutrophils in BM, increased M/E ratio, neutrophils exhibiting myelokathexis-like morphology, and heightened susceptibility to infections.