Some CHI patients respond to diazoxide therapy and we showed previously that diazoxide, which binds at a site distinct from the NBDs and the GBC binding site, has a positive allosteric effect on MgATP binding to SUR1, i.e., diazoxide interacts preferentially with the nucleotide-bound conformation of SUR1 to stabilize an outward-facing configuration with reduced affinity for GBC (9). This evidence concerns the gene ABCC8 and congenital isolated hyperinsulinism.