BACE1 and early-onset autosomal dominant Alzheimer disease: Protein catabolism was connected to multiple other subnetworks in the central body network and contained multiple proteins previously implicated in Alzheimer's disease, including Appl (fly ortholog of APP), beta-site APP-cleaving enzyme (Bace; a fly homolog of BACE1), three members of the cathepsin family (CtsB1, cathD, CtsF/CG12163), and Tau itself identified as a computational network-inferred node.