METTL3 and neoplasm: Further, we used METTL3-WT, METTL3-Δ238, or METTL3-Δ198 to, respectively, complement MDA-MB-231 METTL3 KO cells, and injected these cells orthotopically into the mammary fat pads of mice and performed bi-weekly measurement of tumor volume by caliper.