Cao X, Huang M, Zhu M, et al. - Researchers used Mendelian randomization method, avoiding potential biases, to determine if telomere length (TL) represents the causal risk factor for lung cancer. In two published East Asian genome-wide association studies with 7,127 cases and 6,818 controls, Mendelian randomization analysis was performed. An increased risk of lung cancer was reported in relation to increased weight genetic risk scores (GRS). In various subtypes, a significant link of weight GRS with lung adenocarcinoma risk was evident; while a marginal link was displayed by lung squamous cell carcinoma. A log-linear dose-response link was revealed between increased weight GRS and lung cancer risk in nonlinear analysis. Overall, an elevated lung cancer risk was reported in relation to the presence of a longer TL. In lung carcinogenesis, a likely significant role of those biological mechanisms alterations induced by long TL was suggested.