Resistance to Beclin-1-mediated autophagy arises mainly due to monoallelic loss of the tumor suppressor protein Beclin-1, particularly in sporadic breast, ovary, and prostate tumors, or due to overexpression of the oncoprotein Bcl-2 related to an aggressive clinical tumor phenotype in a variety of cancers [160,161,162,163]. The gene discussed is BECN1; the disease is neoplasm.