Acancer, acute lymphoblastic leukemia, is caused by chromosomal translocation. how does this condition arise? due to addition of extra chromosome in the pair of homozygous chromosomes due to attachment of broken part of one chromosome to another due to duplication of entire set of chromosomes

Ph + ALL, is the largest genetically defined subtype in adult ALL. Until recently, it is acceptable most unfavorable prognosis. Introduction of Imatinib in combination chemotherapy has led to marked improvement in treatment of Ph + ALL. Survival of this leukemia ranges to 40%. The patients with Ph+ ALL have a better prognosis than patients with Ph + high risk ALL , after Imatinib combination with chemotherapy. These improvements are not attirubutable to TKI alone. It depend on also the implementation of chemotherapy, allogeneic stem cell transplantation, second generation TKIs, and molecular monitoring to guide therapeutic decision. Despite these advances, substantial obstacles remain. Ph+ ALL is a group of rapidly develop resistance to TKI because of tyrosine kinase domain mutation. The most important characteristic of survival is age. The incidence of Ph+ ALL increases with age. Because of this, limiting the option of allogeneic stem cell transplantation in a significant proportion of patients.

C- a hypothesis or d- an observation