Indeed, IGKV4-1 has previously been shown to be overrepresented in systemic lupus erythromatosus, celiac disease, and type 1 diabetes (46, 47), and we have also shown that its actual expression in the peripheral repertoire is significantly lower than its frequency of rearrangement in the genomic DNA (48). Here, IGKV4-1 is linked to type 1 diabetes mellitus.