Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Q: Chronic myeloid leukemia (CML) is a progressive and often fatal myeloproliferative neoplasm. The hallmark of CML is an acquired chromosomal translocation known as the Philadelphia chromosome (Ph), which results in the synthesis of the breakpoint cluster region-Abelson murine leukemia (BCR-ABL) fusion oncoprotein, a constitutively active tyrosine kinase. The introduction of imatinib, a tyrosine kinase inhibitor (TKI) that is specific for BCR-ABL, was a major breakthrough in CML therapy. Although most patients respond to first-line imatinib therapy, some experience loss of response (resistance) or require treatment discontinuation because of toxicity (intolerance). For patients with CML, failure on standard-dose imatinib therapy (400 mg daily), imatinib dose escalation (600-800 mg daily) is a second-line option. However, high-dose imatinib is not an appropriate approach for patients who experience drug toxicity, and there remain questions over the durability of responses achieved with this strategy. Alternative second-line options include the TKIs dasatinib and nilotinib. A substantial amount of long-term data for these agents is available. Although both are potent and specific BCR-ABL TKIs, dasatinib and nilotinib exhibit unique pharmacologic profiles and response patterns relative to different patient characteristics, such as disease stage and BCR-ABL mutation status. To optimize therapeutic benefit, clinicians should select treatment based on each patient's historic response, adverse-event tolerance, and risk factors.

A: What tyrosine kinase, involved in a Philadelphia- chromosome positive chronic myelogenous leukemia, is the target of Imatinib (Gleevec)?
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Q: Chronic myeloid leukemia (CML) is arguably the best understood of all human malignancies. Its origins in the hematopoietic stem cell can be traced to a reciprocal translocation involving chromosomes 9 and 22, dubbed the Philadelphia chromosome, which is observed in essentially all patients. The resulting fusion gene, BCR/ABL, encodes an activated tyrosine kinase that can act alone to induce a CML-like syndrome in mouse models. These animal models have validated BCR/ABL as a target for the development of specific pharmaceutical inhibitors. The kinase inhibitor imatinib mesylate (Gleevec) is highly specific, effective, and minimally toxic, but may not effect cures as a single agent, particularly in patients with accelerated and blast-phase disease. Resistance to imatinib can confound therapy. Surprisingly, a high percentage of resistant cases manifest intact or augmented BCR/ABL signaling, suggesting that this oncoprotein, or signaling pathways emanating from it, remain viable targets. Combination chemotherapy is under active investigation, and among the most compelling strategies is dual treatment with agents that both target BCR/ABL signal transduction. BCR/ABL activates Ras, and compounds designed to antagonize Ras function called farnesyl transferase inhibitors (FTIs) have shown potent activity in vitro and in animal models of BCR/ABL-induced leukemia. Initial clinical trials in patients with refractory acute myeloid leukemia and CML in blast crisis have shown significant activity, suggesting that trials combining imatinib and FTIs are warranted.

A: What tyrosine kinase, involved in a Philadelphia- chromosome positive chronic myelogenous leukemia, is the target of Imatinib (Gleevec)?
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Q: Membrane antigens are critical to the pathogenesis of chronic lymphocytic leukemia (CLL) as they facilitate microenvironment homing, proliferation, and survival. Targeting the CLL membrane and associated signaling patterns is a current focus of therapeutic development. Many tumor membrane targets are simultaneously targeted by humoral immunity, thus forming recognizable immunoglobulin responses. We sought to use this immune response to identify novel membrane-associated targets for CLL. Using a novel strategy, we interrogated CLL membrane-specific autologous immunoglobulin G reactivity. Our analysis unveiled lymphocyte cytosolic protein 1 (LCP1), a lymphocyte-specific target that is highly expressed in CLL. LCP1 plays a critical role in B-cell biology by crosslinking F-actin filaments, thereby solidifying cytoskeletal structures and providing a scaffold for critical signaling pathways. Small interfering RNA knockdown of LCP1 blocked migration toward CXCL12 in transwell assays and to bone marrow in an in vivo xenotransplant model, confirming a role for LCP1 in leukemia migration. Furthermore, we demonstrate that the Bruton's tyrosine kinase inhibitor ibrutinib or the PI3K inhibitor idelalisib block B-cell receptor induced activation of LCP1. Our data demonstrate a novel strategy to identify cancer membrane target antigens using humoral anti-tumor immunity. In addition, we identify LCP1 as a membrane-associated target in CLL with confirmed pathogenic significance. This clinical trial was registered at clinicaltrials.gov; study ID number: OSU-0025 OSU-0156.

A:
What is the name of Bruton's tyrosine kinase inhibitor that can be used for treatment of chronic lymphocytic leukemia?
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