Emerging evidence highlights their pivotal roles in tumor progression, immune evasion, and therapeutic resistance, with mucins such as MUC1, MUC5AC, and MUC3A—heavily glycosylated proteins governing cellular adhesion, signaling, and barrier function—showing dysregulation in LUAD and lung squamous cell carcinoma (LUSC) that correlates with aggressive phenotypes (101) (102). The gene discussed is MUC1; the disease is neoplasm.