CD8A and neoplasm: In this study, for the first time, we clarified the characteristics of H3K4me3 modification in LUAD tumor microenvironment based on specific lncRNAs, and found that H3K4me3 modification was closely related to immune cell infiltration, CD4 + T cell and CD8 + T cell activation, EMT, programmed cell death and other tumor-related pathways.