TCGA dataset and Gene Set Enrichment Analysis (GSEA)

The TCGA-LUAD gene expression dataset (TCGA-LUAD.htseq_fpkm.tsv) was downloaded from the Xenahubs database (https://gdc.xenahubs.net/download/TCGA-LUAD.htseq_fpkm.tsv.gz). Tumor samples were classified into high- and low-METTL1 groups using the median METTL1 expression value as the cut-off. GSEA was performed using GSEA 4.0.3 software (http://www.broad.mit.edu/gsea), which was applied with the predefined gene sets. The number of permutations was set at 1,000, and a gene set was considered significantly enriched with a False Discovery Rate score <0.25.