North American ATLL has a distinct mutational landscape. (A) North American ATLL samples (n = 30) and Japanese ATLL cell lines (n = 8) were sequenced by targeted deep next-generation sequencing. Identified mutations are grouped into various functional categories. Corresponding mutations reported in Japanese ATLL are marked in the last row. (B) Location of point mutations in the p53 protein structure. (C) Location of point mutations in the p300 protein structure. Green, blue, and black circles depict missense single nucleotide polymorphisms, splice site single nucleotide polymorphisms, and truncating mutations, respectively. (D) Frequency of mutations in North American and Japanese ATLL. (E) Frequency of epigenetic mutations in North American ATLL and whole-exome sequenced Japanese ATLL cases. *P < .05, North American vs Japanese.