APOE and esophageal squamous cell carcinoma: Some recent studies have reported the expression of these genes (e.g., POSTN, APOE) in subsets of ESCC fibroblasts and macrophages,[5, 8, 9, 62] suggesting the existence of these subsets in ESCC microenvironment, but their role in how they interact with cancer cells or immune cells are largely unexplored.