During autophagic flux, autophagosomes fuse with lysosomes forming autolysosomes which degrade autophagosome contents.55 Using a reporter system where LC3 is fused to both GFP and mCherry (Supplementary Fig. 12),56 we found that mIDH1 glioma cells had increased number of both autophagosomes and autolysosomes when compared with WT-IDH1 cells (autophagosomes > 10-fold increase, P < 0.001; autolysosome > 1.4-fold increase in mIDH1 cells, P < 0.001). Here, IDH1 is linked to central nervous system cancer.