CD9 and diabetes mellitus: Here, we showed that at a 1:1 INSB15-23/hβ2m e-B cell-to-CD8+ T cell ratio, irrespective of whether the e-B cells were CD9+ or CD9− or whether the e-B cells expressed the antigen-specific construct, they were ineffective in delaying or preventing adoptively transferred diabetes by fully activated antigen-specific CD8+ T cells (Figure 7B).