SERPINA1 and diabetes mellitus: For instance, a plasma serpin, Homo sapiens serpinA1, has been found to bind with proteins such as apolipoprotein and glucose-regulated proteins to maintain metabolic homeostasis, and a deficiency in serpinA1 can result in a series of metabolic diseases such as atheroma and diabetes mellitus (Mashiba et al. 2001; Pagetta et al. 2003; Finotti and Pagetta 2004; O’Brien et al. 2020, 2022; Rabekova et al. 2021).