ULK1 and osteosarcoma: Polager et al. demonstrated that in an inducible E2F system in human osteosarcoma (U-2 OS) cells, activation of E2F1 leads to the upregulation of the expression of crucial autophagy-related genes, such as ULK1/ATG1, ATG5, DRAM, and MAP1LC3B/LC3B, and enhances basal autophagy.