TARDBP and amyotrophic lateral sclerosis: To ascertain the source of DNA activating cGAS in response to TDP-43, we immunoprecipitated FLAG-tagged cGAS from HEK293T cells overexpressing WT or ALS mutant TDP-43 (A315T or Q331K; Figure S2A), directly followed by qPCR for the detection of mitochondrial or nuclear DNA (White et al., 2014).