EZH2 and lung cancer: Then the expression of EZH2 protein and mRNA was detected by immunohistochemistry and RNA in situ hybridization, and the relationship between EZH2 gene polymorphism, mRNA and protein expression and clinicopathological parameters of lung cancer brain metastasis was discussed, and the relationship between EZH2 G553C polymorphism and lung cancer brain metastasis was studied.