CD274 and laryngotracheoesophageal cleft: There are different opinions regarding PD-L1 expression; some authors consider it a predictor of a better outcome but only in the early stage of the disease [21]; others consider that its expression is associated with more aggressive characteristics, such as increased tumor size, lymphovascular and perineural invasion, and positive lymph nodes, and, consequently, with a poor prognostic in advanced stages of LC [8-9].