AGT and laryngotracheoesophageal cleft: Several studies have found elevated levels of autoantibodies in LC, including autoantibodies to angiotensin-converting enzyme 2 (ACE2, the receptor for SARS-CoV-2 entry), β2-adrenoceptor, muscarinic M2 receptor, angiotensin II (Ang II) AT1 receptor and angiotensin 1-7 MAS receptor (5).