FASN and neoplasm: Even in the tumor microenvironment lacking oxygen and nutrients, cancer cells can accumulate large amounts of lipids through reprogramming of lipid anabolic metabolism (e.g., up-regulation of key regulators of lipogenesis, such as sterol regulatory element-binding proteins (SREBPs), acetyl-CoA carboxylase (ACC), fatty acid synthase (FASN) and stearoyl-CoA A desaturase 1 (SCD1)) (65, 66), thus providing cell membranes and organelles for cancer cells to proliferate (67).