For instance, in a study comparing purified chemokine isoforms from peripheral blood mononuclear cells and tumor cells, NH2-terminally truncated forms of CXCL5 [CXCL5(8,9-78)], CXCL1 [CXCL1(4,5,6–78)], and CXCL3 [CXCL3(5–73)] were predominantly purified from leukocytes, whereas tumor cells mainly produced the intact chemokine isoforms [199]. This evidence concerns the gene CXCL1 and neoplasm.