Our study demonstrates that this conclusion can be extended to C9orf72 mutations through the gain-of-function mechanisms exerted by novel RNA and/or protein species, and it is consistent with an early transcriptomic study in tissues from C9orf72-ALS patients which provided circumstantial evidence that C9orf72 repeat expansions might affect Golgi-to-ER retrograde transport [37]. Here, C9orf72 is linked to amyotrophic lateral sclerosis.