METTL3 and neoplasm: In addition, we found that high levels of METTL3 in tumour cells (HR: 5.502, P = 0.001) and in tumour-infiltrating immune cells (HR: 6.021, P = 0.001) and a high density of CD33+ MDSCs (HR: 5.755, P = 0.001) were associated with decreased OS.