CD28 and type 1 diabetes mellitus: Furthermore, no significant difference was observed upon Pep3 administration at either day 4 or day 6 of anti-CD3/CD28 stimulation for percentages of CD8+ Teff activated PD1+ cells (S5a and S5d Fig), for CD8+ Teff activated PD1low cells (S5b and S5e Fig) and for CD8+ Teff activated PD1high cells (S5c and S5f Fig) for both HD and type 1 diabetes PBMC.