PGP and cancer: Pgp is the most studied member of the ATP-binding cassette-type membrane transporters and has gained interest due to its ubiquitous nature and owing to its central position as a point of convergence of several deregulated molecular mechanisms [7], such as the PI3K/AKT pathway [8], NF-kB pathway [8, 9] and epigenetic regulations [10, 11] in drug-resistant cancers.