ACTA1 and lung carcinoma: One subtype (MYH11+ α‐SMA+) present in early‐stage lung cancer promotes T‐cell marginalization through the secretion of collagen IV, while the other subtype (FAP+ α‐SMA+) found in late‐stage lung cancer repels T cells through the secretion of collagen XI/XII, exerting an immunosuppressive effect.