TBK1 and type 1 diabetes mellitus: Motivated by these observations ofC-peptide-induced increases in Na+,K+-ATPase activity andassociated improvements in nervous system and renal function, it washypothesised that the low C-peptide levels and reduced Na+,K+-ATPaseactivity in erythrocyte membranes observed in type 1 diabetes may be related.Accordingly, it was found that in patients with type 1 diabetes and completeC-peptide deficiency, erythrocyte activity Na+,K+-ATPasewas consistently lower than healthy controls [19].