PGP and cancer: In these processes, cancer cells shift the expression profile including upregulation of transport‐related proteins (P‐gp, MRP, and BCRP), antiapoptosis‐related proteins (p53, Bcl‐2, and survivin), and DNA repair‐related proteins (topological isomerase: Topo I, Topo II; excision repair cross‐complementation group 1: ERCC I and O6‐methylguanine–DNA methyltransferase: MGMT) 28, 29, 30.