To explore the functional effects of METTL3 and m6A methylation on Cr (VI)-induced carcinogenesis and lung cancer development, METTL3 mRNA expression levels were investigated between tumor tissues and adjacent normal tissues across 22 TCGA tumor types via TIMER, a web tool for variant analysis of The Cancer Genome Atlas (TCGA) data. The gene discussed is METTL3; the disease is neoplasm.