CXCR4 and head and neck squamous cell carcinoma: However, counteracting neutrophil trafficking (by NLRP3 inhibition) or neutrophil aging (by CXCR2 blockade) attenuated tumor progression, whereas supporting neutrophil aging (by blockade of CXCR4) even enhanced tumor growth in SCC VII HNSCC and 4T1 breast cancer (figure 5C).