Here, we describe a series of gene-knockout/knockdown, subcellular localization of autophagy markers, and co-IP experiments demonstrating that ATG101 levels are regulated by HUWE1-mediated ubiquitination and subsequent proteasomal degradation in cancer cells and this degradation pathway can markedly suppress autophagy, leading to reduced cell viability under metabolic stress. The gene discussed is HUWE1; the disease is cancer.