When analyzing the IgM memory B cells, the ratio of IgM+ memory B cell (CD19+CD27+IgM+) percentages following CpG stimulation over unstimulated cells tended to significantly increase in T1D patients harboring the C/T PTPN22 variant compared to C/C individuals (KS-test p<0.05; one way ANOVA with Kruskal-Wallis test and Dunn’s multiple comparison test p = 0.063) (Figure 2D, Figure S4, Figure S7). This evidence concerns the gene CD19 and type 1 diabetes mellitus.