After interacting with tumor cells, macrophages can undergo a phenotypic shift from expressing M1 markers to increasing expression of M2 markers such as Arg1 and CD163.479 Interestingly, even the death of tumor cells can promote M2 polarization within the microenvironment.480,481 In pancreatic ductal adenocarcinoma (PDAC), extracellular vesicles release the KRASG12D protein into the microenvironment during autophagy-dependent ferroptosis. This evidence concerns the gene ARG1 and neoplasm.