INS and diabetes mellitus: Originally developed to follow insulin secretion from Langerhans islets in Diabetes treatment (Speier et al., 2008a; Rodriguez-Diaz et al., 2012), the ACE model allows longitudinal, non-invasive in vivo imaging of anti-islet immune responses with single-cell resolution in real time (Abdulreda et al., 2013; Abdulreda et al., 2019).