CXCR2 and colorectal carcinoma: Furthermore, after treatment with 5-FU, the expression levels of CXCL8 mRNA in HCT116 and HCT116/FU cells were 3.7- and 4-fold higher, respectively, than those in untreated cells, indicating that CXCL8 was upregulated in the chemoresistant subline of the CRC cell line HCT116, and modulation of the CXCR2 pathway was able to become a target for proliferation inhibition of chemoresistant CRC cells.