Studies have shown that gefitinib downregulates the expression of peroxisome proliferator-activated receptor alpha (PPARα), LXRα, and ABCA1, leading to dysregulation of cholesterol efflux and induction of drug resistance in NSCLC cell lines.283 The exact relationship between cholesterol accumulation in cancer cells and drug resistance is unclear, but the combination of fenofibrate, a lipid-lowering drug that can upregulate the PPARα expression, and gefitinib can promote apoptosis in resistant cells. This evidence concerns the gene PPARA and non-small cell lung carcinoma.