PPBP and colorectal carcinoma: Further, a marked downregulation of CXCL1, CXCL2, and CXCL3 expression was observed in C2–4 KO CRC tissues relative to WT CRC tissues, whereas the expression levels of CXCL5, CXCL7, and CXCL15 remained unchanged between C2–4 KO and WT CRC tissues (Figure S9A, Supporting Information).