As shown in Fig. 2C and Fig. S2A-C, the levels of LC3B-II, SQSTM1 and ubiquitin were increased, while LAMP1 protein level was significantly decreased in the muscle of MNGIE patients, indicating impaired lysosomal function and blocked autophagic flux. This evidence concerns the gene LAMP1 and mitochondrial neurogastrointestinal encephalomyopathy.