CXCL9 and neoplasm: Recent discoveries reveal several mechanisms, such as epigenetic silencing of CCL5, CXCL9, and CXCL10 in different tumor entities [52,74] or post-translational cleavage of those same chemokines by enzymes such as dipeptidylpeptidase 4 or matrix metalloprotease-9 [75,76,77].