ATG5 and neoplasm: This cytoprotective autophagy can be alleviated trough chemical (e.g. BAF-A1, CQ, 3-MA, or wortmannin) and genetic inhibition of essential autophagy-related genes (e.g. ATG3, ATG5, ATG7, or Beclin 1) or autophagy regulators (e.g. CHOP), leading to significant suppression of PDT-resistance of tumor cells (Table 1).