KRT14 and bronchiolitis obliterans syndrome: Our group and others observed that Krt14+ cell abundance increases on the airway surface in multiple lung pathologies, such as in idiopathic pulmonary fibrosis, BO occurring after lung transplantation, restrictive allograft syndrome (RAS) after lung transplantation, and in injury models like SO2 and Cl2 gas exposure, and injuries caused by naphthalene and polidocanol exposure (8, 10–14).