PRKCE and amyotrophic lateral sclerosis: Considering that the SALS2 subcluster was the only one showing significant deregulation in SOD1 expression level [16,38], we decided to inspect PKCε expression in vitro in the widely used murine cellular humanized ALS model, i.e., NSC-34 over-expressing WT or mutated human SOD1-G93A under doxycycline activation, as previously reported [39].