CXCR2 and cancer: Abnormal elevations of CXCL5 and/or CXCR2 proteins have been noted in as many as 14 distinct malignant tumor types, including but not limited to CRC,263, 264 nonsmall cell lung cancer,265 breast cancer,266 bladder cancer,267 nasopharyngeal carcinoma,268 and so on.