Common variation in the TREM2 locus has also been associated by GWAS with C-reactive protein levels (61) and potential associations of p.R47H with FTD, ALS and Parkinson's disease have also been reported (62–65), suggesting a potential role for TREM2 across different neurodegenerative disorders. This evidence concerns the gene TREM2 and amyotrophic lateral sclerosis.