SOD1 and amyotrophic lateral sclerosis: A recent study on the SOD1-G93A mice in which the scAAV9-hIGF-1 was intramuscularly injected into transgenic cells and administered to cell lines expressing the ∼ 25-kDa C-terminal fragment of transactive response DNA-binding protein (TDP-25) states that IGF-1 vigorously protects mitochondria from apoptosis and upregulates mitophagy in mouse and cell models of ALS [9].