PGP and cancer: Sublines resistant to PTX (MCF-7/Pac) and vincristine (MCF-7/Vinc) were developed from drug-sensitive MCF-7/S cells to reproduce chemoresistance in this type of cancer and thus analyse whether the extracts of Fomes fomentarius and Tricholoma anatolicum combined with chemotherapeutics were able to regulate P-gp activity and increase the cells’ sensitivity to the drugs.