BRAF and acute lymphoblastic leukemia: The CNA often involved large (>1 Mb) regions (95%, 20/21) of chromosomes recurrently abnormal in iAMP21-ALL, for example loss/deletion of chromosomes 7/7q (BRAF locus) and 11q (CBL locus).14 One focal CNA (75 kb) targeted only the FLT3 locus (patient 9), although the other allele was not mutated.