However, only 58% of individuals with HNF1A/HNF4A-MODY were on diet or sulfonylurea alone at 2 years and, overall, just 36% of individuals with HNF1A/HNF4A-MODY who changed treatment achieved the good glycaemic control (≤58 mmol/mol [≤7.5%]) needed to avoid diabetes complications. Here, HNF1A is linked to diabetes mellitus.