SOD1 and amyotrophic lateral sclerosis: Lower expression of 3′ tRFs (except 3′ tRF SerCGA in the SOD1 ALS model and 3′ tRF Gly in the FTD model), formed by cleavage in the T loop of the tRNA, in the ALS and FTD animal models suggests lower activity of DICER or other RNases in the mutant than in WT.