NANOG and teratoma: In nude mice, METTL1‐KD hiPSCs clearly enhance teratoma formation by promoting cell proliferation and angiogenesis by decreasing the mRNA levels of the stem cell transcription factors recombinant octamer binding transcription factor 4 (Oct4), Nanog and sex‐determining region Y (Sox2), providing novel insight into the potential role of METTL1 in teratoma treatment.50