Gene silencing using small interfering RNA (siRNA) usually knocks down Beclin1, ATG5, ATG7, ATG8 and ATG12 to inhibit autophagy and sensitizes the drug-resistant cancers [132–135], while pharmacological inhibitors generally use 3-methyladenine (3-MA), bafilomycin A1 (BafA) and chloroquine (CQ) to inhibit the formation of autophagosome [132–134, 136] and sensitize the resistant cancer cells to chemotherapy. Here, ATG5 is linked to cancer.