PPIF and amyotrophic lateral sclerosis: CsA is an FDA-approved immunosuppressive agent, which might be used during solid organ transplantations, for rheumatoid arthritis, psoriasis, ALS, nephrotic syndrome, graft vs. host disease, etc. Moreover, CsA is quite toxic, and its application has a lot of side effects, so research and development of new non-immunosuppressive CypD and mPTP inhibitors remains an important and challenging task.