MME and achalasia-alacrima syndrome: However, there is increasing evidence that NEP substrates and/or products, including brain or natriuretic peptides, may serve as biomarkers or prognostic indicators after surgery of human AAAs (Rajagopalan et al., 2008; Vetrugno et al., 2012; Bryce et al., 2013; Folsom et al., 2015; Acosta et al., 2018; Chan et al., 2019).