PGP and acute myeloid leukemia: In this work, we intend to further underline the importance of blocking the spread of P-gp-mediated drug resistance and explore the possible chemosensitizing effects of natural compounds that act as inhibitors of the vesiculation process, in two different multidrug-resistant cell models of breast cancer (MCF-7R) and acute myeloid leukemia (HL-60R).