The well-studied mechanism of multidrug resistance in cancer cells is the P-glycoprotein (P-gp), an over-expression of membrane protein belonging to ATP-binding cassette (ABC) transporters, which could effectively pump anticancer agents out of cells against a concentration gradient, thereby reducing the drug concentration in the target site and eventually diminishes therapeutical efficacy (Meads et al., 2009; Fletcher et al., 2010; Yin et al., 2012). Here, PGP is linked to cancer.