KRAS and cancer: In addition, recent study developed chemogenitic-based switchable CAR-T cells targeting CD19 positive cancer cells in in vitro and in vivo using anti-CD 19 hepatitis C virus NS3 protease (HSV-NS3) between the single-chain variable fragment (scFV) demonstrated control of CAR-T activity in the presence and absence of HCV-NS3 inhibitor asunaprevir in eliminating CD19 positive tumor cells (118).