Among these, perhaps best‐documented are ACE inhibitor‐induced angioedema (Byrd et al., 2006; Campbell, 2018) and pathogenic BBB opening and edema formation during acute neurodegenerative disorders such as stroke and traumatic brain injury (Donkin et al., 2009; Groger et al., 2005; Jayaraman et al., 2020; Sorby‐Adams et al., 2019; Trabold et al., 2010). The gene discussed is ACE; the disease is angioedema.