CD274 and laryngotracheoesophageal cleft: Dysregulation of several pathways is involved in the process of LC occurrence and development, mainly including Wnt (22), P13/Akt (23), Notch (25), PD-1/PD-L1 (4), NF-KB (26), Hippo (27), MAPK (17), Hedgehog (29) and AMPK (30).