The remaining gene, MDN1, corresponded to a region which has a stronger association signal in the RA-ImmunoChip than RA-GWAS dataset, which may reflect the greater power of direct genotyping vs. imputation, given that the RA-ImmunoChip signal is echoed in ATD and T1D (Additional file 2: Figure S8). Here, MDN1 is linked to type 1 diabetes mellitus.