ATG7 and metastatic malignant neoplasm: As far as the role of autophagy in HCC development is concerned, it was reported that homozygous deficient mice for the autophagy genes ATG5 or ATG7 develop benign liver tumors that do not progress to metastatic cancer, which suggests that loss of autophagy may be sufficient for the initiation of tumorigenesis, but residual autophagy is required for the progression to cancer [6].