Some studies have suggested that P-gp and BCRP can be downregulated by PI3K110α and -110β to restore the drug sensitivity of drug-resistant human epidermoid carcinoma and non-small cell lung cancer, and that ABC family proteins and AKT may play an independent role in enhancing MDR (27–29). The gene discussed is ABCG2; the disease is non-small cell lung carcinoma.