However, some functional perturbations appeared to be specific to T1DM up-DEGs, such as antigen processing and presentation capacity by B cells, driven by over-expression of a MHC class II cluster including HLA-DM, HLA-DO, HLA-DRB1, HLA-DQB1/HLA-DQA1, CD74, and CTSS [Fig. 3d; Additional file 1: Fig. S6b; [71]]. This evidence concerns the gene CTSS and type 1 diabetes mellitus.