Yagi T, et al. - Investigators assessed the expression of two M2-like macrophage markers (CD163 and CD204) and programmed death ligand 1 (PD-L1) on tumor cells by immunostaining to quantify the clinical and prognostic characteristics of tumor-associated macrophages (TAMs), and also the relationship between TAMs and PD-L1 in esophageal cancer. They found an association of high density of CD163 (n = 160) or CD204 (n = 146) with significantly worse overall survival vs low expression. They found that no prognostic impact of TAMs was significantly modified by any clinical factor. They noticed a relation of high TAM density in esophageal cancer tissues with shorter survival, implying a prognostic biomarker role for TAMs. An increase in PD-L1 expression in tumor cells was reported linked to high TAM density.