PGP and central nervous system cancer: Given that ATP-dependent membrane transporters such as P-gp and MRP1 mediate drug efflux and limit chemotherapeutic efficacy (Gottesman et al., 2002; Robey et al., 2018), these findings indicate CHR’s potential to counteract TMZ-induced MDR, a notable factor in treatment resistance in gliomas (Rich and Bigner, 2004).