TIGIT and squamous cell lung carcinoma: In certain cancers, such as colorectal cancer, the upregulation of these receptors has been linked to disease progression [25], while in lung squamous cell carcinoma, a strong correlation exists between PD-1 and TIGIT densities, and the coexpression of their ligands holds promise as both a prognostic factor in the disease and a potential predictive biomarker for dual-targeting immunotherapy [26].