FAS and cancer: In fact, in the early inflammatory phase of cancer onset, TAMs show an M1-like phenotype and are localized in the normoxic region of the tumor, exhibiting preponderance of glycolysis, fatty acid synthesis (FAS), and PPP with a truncated tri-carboxylic acid cycle, leading to accumulation of succinate and citrate, while in the later stages of cancer, M1-like macrophages are polarized to an M2-like phenotype with greater concentrations in the hypoxic zones of the tumor, which mainly use fatty acid oxidation (FAO) and mitochondrial biogenesis [66,71].