Structural breakpoints at 2q and 5q, and candidate genomes in ATL. Structural breakpoints with chromosome deletions and additional chromosome material of unknown origin. (A) Chromosome 2. Mutations in CD28, CTLA4, and ICOS frequently caused fusion, and mutations in PDCD1 frequently caused deletion. (B) Chromosome 5. Mutations in CSNK1A1 and GABRG2 frequently caused fusion, and mutations in MAN2A1 frequently caused deletion.