We previously reported that SNP rs5770917 located between the carnitine palmitoyltransferase 1B (CPT1B) and choline kinase beta (CHKB) genes was associated with susceptibility to narcolepsy with cataplexy after performing a genome-wide association study in Japanese and Korean populations (P = 1.4×10−7; odds ratio = 1.68) [1]. Here, CPT1B is linked to narcolepsy.