MAPT and Alzheimer disease: Further, there is increasing recognition that TBI is a major modifiable risk factor for neurodegeneration, including Alzheimer’s disease [43] and chronic traumatic encephalopathy [46], Here, progressive axonopathy is thought to be a key driver of TBI-related neurodegeneration since potential protein substrates for tau and amyloid pathologies may have their start in the milieu of axonal injury [25, 46].