AMBRA1 and neoplasm: Since tumor suppressive activity of AMBRA1 has been attributed to its role as substrate receptor for a cullin4-RING E3 ubiquitin ligase (CRL4) [40–42], we next aimed to delineate changes in protein levels of cell cycle regulators upon loss of AMBRA1 in ATRT cells with clear AMBRA1-associated tumor suppressive activity (hereafter referred to as AMBRA1 responders), and compare those to ATRT cells where loss of AMBRA1 does not show any proliferative or cell cycle-associated effects (hereafter referred to as AMBRA1 non-responders).