C9orf72 and amyotrophic lateral sclerosis: In the following years, new antibodies have been developed that have revealed a clear decrease in C9ORF72 protein levels in the frontal cortex from FTD or ALS patients with C9ORF72 repeat expansion compared to controls (Waite et al., 2014; Xiao et al., 2015; Saberi et al., 2018).