For example, SLC24A3 and KCNK5 are involved in ion channel activity, and RNF213 is involved in metal ion homoeostasis. It is interesting given all three genes implicated in a rare monogenic form of migraine—familial hemiplegic migraine (FHM)—are involved in ion transport (Nyholt et al. 2017). This evidence concerns the gene KCNK5 and familial hemiplegic migraine.