INS and type 1 diabetes mellitus: We used the carboxyfluorescein succinimidyl ester (CFSE)-based proliferation assay (35) to determine if the responses to the proinsulin HIPs we had identified were detectable in the PBMCs of 10 individuals with T1D and 10 individuals without T1D who expressed the HLA-DR4-DQ8 haplotype (Tables 7 and 8).