MNX1 and amyotrophic lateral sclerosis: Increased mtphagy dye signals indicated improved mitophagy in Hb9::GFP+ MNs (Fig. 5E,F), with abundant mitolysosome-like structures (Fig. 5G, green arrow), and fewer damaged mitochondria (Fig. 5G, red and yellow arrows), suggesting that ISO activates mitophagy in ALS MNs.