In the case of proteostasis, expression of ALS-associated profilin-1 mutants has been shown to lead to the formation and seeding of TDP-43 positive proteinaceous aggregates in cultured cells (Wu et al., 2012; Smith et al., 2015; Tanaka and Hasegawa, 2016). Here, PFN1 is linked to amyotrophic lateral sclerosis.