Blood samples were obtained from individuals with type 1 diabetes enrolled on the ‘Double diabEtes and adVErse cLinical Outcome: identification of mechanistic Pathways’ (DEVELOP) study with insulin resistance assessed as estimated glucose disposal rate (eGDR), whereby eGDR >8 or <6 mg kg−1 min−1 indicates normal insulin sensitivity or advanced insulin resistance, respectively. The gene discussed is INS; the disease is type 1 diabetes mellitus.