CXCL1 and breast cancer: Additionally, CXCL1, a proangiogenic CXC-type chemokine, is present in many cancer types, including breast, lung, pancreatic, colorectal and prostate cancers and several studies reported that CXCL1 had been identified as being overexpressed by breast cancer cells with an elevated potential to metastasize to the lung [54–58].