ABCC9 encodes SUR2, a regulatory subunit of ATP-sensitive potassium (KATP) channels that form complexes with KCNJ11 or KCNJ8 to create cardiac and smooth muscle-type channels 1. KCNJ11 forms the channel pore while ABCC9 is required for channel activation and regulation 1. ABCC9/KCNJ8-containing KATP channels modulate brain vascular smooth muscle cell differentiation and neurovascular coupling through regulation of intracellular calcium oscillations 2. Loss-of-function mutations in ABCC9 cause autosomal recessive intellectual disability and myopathy syndrome (AIMS), characterized by psychomotor delay, intellectual disability, microcephaly, white matter abnormalities, seizures, and muscle weakness 3. ABCC9 genetic variants are associated with dilated cardiomyopathy 4 and limbic-predominant age-related TDP-43 encephalopathy (LATE), a common dementia pathology affecting approximately 25% of elderly brains 5. ABCC9 is widely expressed across brain cell types including neurons, astrocytes, and vascular cells, serving as a metabolic sensor and regulator of the neurovascular unit 6. Knockout of ABCC9 increases doxorubicin-induced cardiotoxicity susceptibility in hiPSC-derived cardiomyocytes, suggesting roles in drug metabolism 7. Disease-associated polymorphisms function as expression quantitative trait loci, altering ABCC9 transcript levels and 3' UTR usage through microRNA targeting 8.