FN1 and neoplasm: FN1, encoding another ECM protein that was associated with tumor-promoting macrophages in gastric cancer,60 was upregulated in Arms B and C, as was the metabolic regulator INSIG1. Altogether these findings suggest that anti-PD1 induces potent gene expression changes that alter TAM function, metabolism, and ECM interactions via modulation of cytoskeletal and ECM components.