TMEM87B and Cluster headache: In addition, among the genes that may be potentially affected by variants in MERTK, i.e., with significant eQTL expression, TMEM87B (transmembrane protein 87B) and FBLN7 (Fibulin 7) have been identified in prior GWASs via gene-based analysis or eQTL analysis [6, 7], suggesting their involvement in cluster headache.