ENA-001 (formerly known as GAL021) is an agnostic respiratory stimulant that increases breathing activity by blocking calcium-activated potassium channels (BK-channels) at the carotid bodies.2–6 In previous studies, it was demonstrated that ENA-001 can reverse respiratory depression induced by opioids in healthy volunteers and monkeys.4–6 Glomus type-1 carotid body cells express BK-channels and release neurotransmitters upon blockade of these channels. This evidence concerns the gene KCNMA1 and respiratory depression.