NEIL1 is an important editing target of ADAR1 in MM. (A, top) Distribution of the number of editing sites across different regions on the transcript. (Bottom) The average number of editing sites only on the exon region of mRNA in patients from different disease stages. (B) Venn diagram illustrating the number of nonsynonymous editing (identified from RNA-seq) in ADAR1-overexpressed (MM1s) and knockdown (U266) HMCLs. KD, knockdown; OE, overexpression. (C) Sequence chromatogram of NEIL1 demonstrating the A726G editing frequencies in MM1s and U266 on ADAR1 overexpression and knockdown, respectively. (D) RNA-immunoprecipitation assay documenting the fold enrichment of NEIL1 transcripts on ADAR1 protein in MM1s and U266 at the basal state and when ADAR1 was OE or KD. RIP2 and RIP3 are results from 2 different sets of primers encompassing nucleotide 726 of NEIL1 mRNA. (E) Venn diagram presenting the statistics of NEIL1 editing across the whole mRNA and at the specific site of interest (A726G). (F) The frequency of NEIL1 editing (A726G) in the transcripts of patients (in-house) from different disease stages. **P < .05; ***P < .001.