RPS27A and amyotrophic lateral sclerosis: The involvement of dysregulated immune system, proteasome activity, and altered cytoskeleton remodeling in driving the ALS phenotype also emerged in the PPI network analysis that highlights the central role of multiple ubiquitin coding genes (i.e., UBA52, RPS27A, UBC, and UBB) identified as the most interconnected nodes in the network (Figure 3a).