IL4 and laryngotracheoesophageal cleft: In conjunction with our non-significant findings pertaining to CD8+ T cells, Treg infiltration, MVD, and the concentrations of TNF-α, IFN-γ, IL-4, and IL-10, these results underscore the challenges of using PD-1 inhibition as a monotherapy in LC, where low PD-1/PD-L1 expression may limit the ability of the immune system to mount an effective antitumor response.