Breast cancer cells disrupt normal lipid metabolism by increasing de novo synthesis of FA evident by increased expression of various enzymes regulating this pathway, i.e. Acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS) [31–33] and stearoyl CoA-desaturase-1 (SCD-1), which catalyses the conversion of saturated FA (SFA), e.g. palmitic and stearic acid, to palmitoleic and oleic acid [53–55]. The gene discussed is FASN; the disease is breast cancer.