Remarkably, C21orf2 was also recently identified as an ALS-associated gene [14], and autosomal recessive mutations in both NEK1 and C21orf2 are linked to a skeletal disorder, axial spondylometaphyseal dysplasia [69,70], further highlighting the genetic and functional link between these genes and proteins. This evidence concerns the gene NEK1 and amyotrophic lateral sclerosis.