This result was confirmed by the findings that the risk allele frequency of BACH2 in the six patients was significantly higher than that in the non‐diabetic control participants (n = 179) and type 2 diabetes with or without insulin treatment (n = 154 or n = 152; P = 0.035, 0.034 or 0.037, respectively). Here, BACH2 is linked to type 2 diabetes mellitus.