TMC8 and leukocyte adhesion deficiency: Focal epithelial hyperplasia has been associated with leukocyte adhesion deficiency 84, the human leukocyte antigen (HLA)‐DRB1*0404 allele 85, and recently also with mutations in adjacent transmembrane channel‐like protein (TMC) TMC6 or TMC8 (also called EVER1 and EVER2) genes located on chromosome 17q25 86.