Anti‐insulin antibodies were observed in patients with diabetes treated with exogenous insulin, leading to immunological resistance and poor glycaemic control.14, 15 A similar experience was found in patients treated with growth hormone therapy and with enzyme replacement in Gaucher's disease.16, 17, 18 Hence, our finding is in keeping with this phenomenon and may explain some of the side effects seen in the RoSA study. This evidence concerns the gene GH1 and diabetes mellitus.