Similar to for example water, which can condense from vapor to fluid and freeze from fluid to solid, ALS- and FTLD- related RNA-binding proteins (e.g., TDP-43, hnRNPs and FUS) can undergo a similar phenomenon in vitro and in cell culture [15, 79, 83, 94] (Fig. 2c). This evidence concerns the gene FUS and amyotrophic lateral sclerosis.