Perspectives on topology of the human m^sup 1^A methylome at single nucleotide resolution

N1-methyladenosine was recently reported to be a chemical modification in mRNA. However, while we identified hundreds of m1A sites in the human transcriptome in a previous work, others have detected only nine sites in cytosolic and mitochondrial mRNAs. Herein, we provide additional evidence that hundreds of m1A sites are present in the human transcriptome. Moreover, we show that both the improper bioinformatic tools and the poor quality of sequencing data in a previous study led to the failure in identifying the majority of m1A sites. Our analysis hence provides an explanation of the divergence in the prevalence of this newly discovered mRNA mark.