illustrated that exposure of a subset of breast cancer cells to hypoxia induced ALKBH5 expression in an HIF‐dependent manner, which led to reduction in m6A modification of NANOG mRNA and enhanced NANOG mRNA stability.72 In addition, ALKBH5 depletion impaired hypoxia‐induced BCSCs enrichment and tumour formation.72 Further study showed that ALKBH5 expression was required for breast cancer initiation and lung metastasis.73 Zinc finger protein 217 (also known as ZNF217) plays a complementary role with ALKBH5 in negatively regulating m6A methylation. Here, NANOG is linked to breast cancer.