FISH experiments. 1a. ETV6 break apart FISH. Arrows indicate the split signal for one allele, the arrow head marks the fusion signal of the wildtype allele. 1b. WCP of chromosomes 12 (red) and 15 (green). The arrows indicate the reciprocal translocation giving rise to derivate chromosomes der(12) and der(15). The arrow head marks the additional material of chromosome 12 on chromosome 10.