[1] United Med & Dent Sch Guys & St Thomas Hosp, St Thomas Hosp, St Johns Inst Dermatol, Dept Cell Pathol, London SE1 7EH, England
[2] Thomas Jefferson Univ, Jefferson Med Coll, Epithelial Genet Grp, Philadelphia, PA 19107 USA
[3] Guys Hosp, Dept Otolaryngol, London SE1 9RT, England
[4] Hosp Sick Children, London WC1N 3JH, England
[5] Vienna Bioctr, Inst Biochem & Mol Cell Biol, Vienna, Austria
[6] St Bartholomews, Dept Dermatol, London, England
[7] St Bartholomews, Dept Morbid Anat, London, England
[8] Univ London Queen Mary & Westfield Coll, Royal London Sch Med & Dent, London E1 4NS, England
[9] Univ Dundee, Dept Anat, Cell Struct Res Grp, Dundee, Scotland
[10] Univ Dundee, Dept Physiol, Dundee, Scotland
[11] Thomas Jefferson Univ, Jefferson Inst Mol Med, Dept Dermatol & Cutaneous Biol, Philadelphia, PA 19107 USA
[12] Thomas Jefferson Univ, Jefferson Inst Mol Med, Dept Mol Pharmacol & Biochem, Philadelphia, PA 19107 USA