Acknowledgement
The authors are grateful to Yoko Suzuki, Yasuo Sato and others in the laboratory at Tokyo Metropolitan Neurological Hospital for their excellent technical assistance. This work was supported by JSPS KAKENHI (Grant-in-Aid for Scientific Research (B)) and the Joint Program for ALS Research, Tokyo Metropolitan Institute of Medical Science.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.