CD4 and diabetes mellitus: A survey of human insulitis reveals a diverse array of suspects, composed of CD8+ and CD4+ T cells, B cells, macrophages, and other immune cells (17–22) [along with data sets from consortia such as the Network of Pancreatic Organ Donors with Diabetes (nPOD; https://www.jdrfnpod.org/), the Exeter Archival Diabetes Biobank (EADB; https://foulis.vub.ac.be/) and the Human Islet Research Network (HIRN; https://hirnetwork.org/)].