TERT and lung cancer: Contrasting this protective role, 85–90% of lung cancers exhibit pathological telomerase reactivation via telomerase reverse transcriptase (TERT, catalytic subunit) overexpression and telomerase RNA component (TERC, RNA template) dysregulation, enabling replicative immortality; Reactivation mechanisms include recurrent TERT promoter mutations (C228T/C250T) and epigenetic remodeling of telomere maintenance genes (34).