The chitinase proteins (Chitotriosidase 1, Chitinase 3‐like protein 1, and Chitinase 3‐like protein 2), GPNMB, and CD44 were all significantly increased in abundance in both sporadic and C9orf72 ALS, but only Chitinase 3‐like protein 1 was significantly raised in sporadic FTD. Here, C9orf72 is linked to amyotrophic lateral sclerosis.