ATP6V1A and osteosarcoma: Human U2OS osteosarcoma cells stably expressing a GFP-LC3 fusion protein exhibit GFP-LC3 dots in the cytoplasm (corresponding to “autophagic puncta”)42 in response to the autophagy inducer torin1 (TOR, an inhibitor of mechanistic target of rapamycin, mTOR) and the lysosomal inhibitor bafilomycin A1 (BafA1, an inhibitor of the vacuolar-type H+-ATPase (V-ATPase) that is required for lysosomal acidification)43.