Furthermore, the ubiquitous distribution of plasmin, its structural similarities to trypsin (Mangione et al., 2018) and the reported activation of plasminogen activation system (PAS) in other amyloid-related disorders, such as Alzheimer's disease (Tucker et al., 2000) and immunoglobulin light chain (AL) amyloidosis (Mumford et al., 2000; Bouma et al., 2007; Uchiba et al., 2009) also indicate that this protease could perform a key role in TTR amyloidogenesis. Here, TTR is linked to early-onset autosomal dominant Alzheimer disease.