The function of ABCC9 (ATP binding cassette subfamily C member 9, Ensembl gene identifier ENSG00000069431) is as follows. Subunit of ATP-sensitive potassium channels (KATP). Can form cardiac and smooth muscle-type KATP channels with KCNJ11. KCNJ11 forms the channel pore while ABCC9 is required for activation and regulation (PubMed:9831708). Can form a sulfonylurea-sensitive but ATP-insensitive potassium channel with KCNJ8 (By similarity). .