PGP and leukemia: In both the murine leukemia P388ADR and human leukemia K562/P-gp models, cotreatment (EC31 + DOX) significantly prolonged the survival of the mice, with an ILS of 30.3% (*** p < 0.001) and 15.6% (** p < 0.01), as compared to the DOX alone group (Figure 6A,B), respectively.