MYC and amyotrophic lateral sclerosis: Consistent with the co-localization between HDAC6 and poly (GA) in c9FTD/ALS patients, GFP-(GA)50 co-immunoprecipitated with myc-HDAC6, while GFP-(GP)47 and GFP-(GR)50 did not, despite a similar level of GFP expression in all cell lysates (Figure 1D).