Furthermore, TAS3351 is not a substrate of P-glycoprotein (P-gp) and the breast cancer-resistant protein (BCRP) and exhibits significant brain penetrability, resulting in anti-tumor efficacy in mice with intracranial allografts.<h4>Conclusions</h4>These findings indicate that TAS3351 is a promising therapeutic candidate for patients with NSCLC whose tumors have relapsed or are refractory to treatment due to the C797S and T790M mutations, and the brain metastases. The gene discussed is PGP; the disease is non-small cell lung carcinoma.