The chromosome 22 product is much shorter and is called a Philadelphia chromosome . The break point on chromosome 9 is near the oncogene c-abl and that oncogene resides on the Philadelphia chromosome after the translocation event. In these cases, the breakpoint on chromosome 8 is always very near the c-myc oncogene, and the translocated segment is relocated on the other chromosomes in the vicinity of antibody producing genes. In neither case, Burkitt's lymphoma or chronic myelogenous leukemia, is the reason that the cancer appears understood, although the placement of the oncogene in a new chromosomal location probably has an effect. For example, some of the Burkitt lymphomas are associated with a translocation of the oncogene into the vicinity of an enhancer element involved with antibody expression.
Enhancers are sequences which greatly increase the expression of genes which are located nearby.
Possibly this enhancer is greatly increasing the expression of the c-myc oncogene product which leads to the cancerous state.