CXCL9 and cancer: TAM are often the most abundant cell types in tumors, with many of them being pro‐tumorigenic.[2] Recent scRNA sequencing studies have shed light on the composition of human myeloid subsets in cancers[1] and other inflammatory diseases.[11] One of the overarching discoveries of these studies was i) the high SPP1 expression in undesirable macrophages and ii) the virtual exclusiveness of SPP1 with other biomarkers of favorable macrophage subtypes (e.g., CXCL9).