CSF1 and neoplasm: Since bulk tumor-derived transcriptomic data quantify total gene expression from heterogenous cell types, CSF1R and CSF1 transcripts could be mostly derived from the stromal tumor-associated macrophages (which express this highly in comparison to relatively low expression in carcinoma cells); CSF1, in addition, is also expressed by several stromal cells such as fibroblasts, endothelial cells, and smooth muscle cells [61].