CXCR2 and neoplasm: However, CXCR1 expression in primary NB tumors and cell lines is generally lower and more variable compared to CXCR2, which is consistently upregulated in NB and plays a dominant role in recruiting neutrophils and myeloid-derived suppressor cells (MDSCs) to the tumor microenvironment, promoting angiogenesis, inflammation, and tumor progression [4,5].