We summarized the abnormal alterations of a common RNA modification, m6A modification, in tumor cells that can result in dysregulation of gene expression, such as ABC transporter gene family, OATP transporter genes, DNA damage and repair genes, autophagy-inducing genes, anti-apoptotic and pro-apoptotic genes, which contribute to cancer recurrence and therapeutic resistance. This evidence concerns the gene ABCG2 and neoplasm.