In our research, by using The Cancer Genome Atlas (TCGA), the Chinese Glioma Genome Atlas (CGGA), Rembrandt dataset and Gravendeel/GSE16011 dataset, we assessed the expression level (in conjunction with experimental examination of LGG patient samples), methylation level and copy-number variations of METTL21B in LGG tissues, analyzed the association between prognosis and expression of METTL21B, and explored the underlying molecular mechanisms of METTL21B in LGG. This evidence concerns the gene EEF1AKMT3 and cancer.