CCL4 and neoplasm: Among other notable DEGs, PD-L1+ clusters were also defined by high expression of many transcripts encoding for chemokines that have been shown to be released by suppressive tumor-associated neutrophils (22) such as Ccl2, Ccl3, Ccl4, Ccl5, Ccl12, Ccl17, and Cxcl16 (table S1).