CD28 and type 1 diabetes mellitus: In addition, no significant difference was observed upon Pep3 administration at 4 days of anti-CD3/CD28 stimulation in percentages of CD4+ Teff activated PD1+ cells (S7a Fig), CD4+ Teff activated PD1 low cells (S7b Fig) and CD4+ Teff activated PD1high cells (S7c Fig) for both HD and type 1 diabetes PBMC.