PPBP and colorectal carcinoma: Several chemoattractants, such as CXCL1, CXCL2, CXCL3, CXCL5, CXCL7, and CXCL15, have been reported to recruit MDSCs through binding to CXCR2.[37] Transcriptomic analysis revealed a significant downregulation of CXCL1, CXCL2, CXCL3, and CXCL5 expression in C2–4 KO CRC tissues compared to WT and C1 KO CRC tissues (Figure 6D).