Detailed Instructions: Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
See one example below:
Problem: In 1582 the united provinces invited francis, duke of anjou to lead them; but after a failed attempt to take antwerp in 1583, the duke left the netherlands again. after the assassination of william of orange (10 july 1584), both henry iii of france and elizabeth i of england declined the offer of sovereignty. however, the latter agreed to turn the united provinces into a protectorate of england (treaty of nonsuch, 1585), and sent the earl of leicester as governor-general. this was unsuccessful and in 1588 the provinces became a confederacy. the union of utrecht is regarded as the foundation of the republic of the seven united provinces, which was not recognized by the spanish empire until the peace of westphalia in 1648.
Solution: In what year did francis, duke of anjou leave the netherlands?
Explanation: The generated question is perfect. Because the question is based on second sentence of the input passage and its answer is 1583.

Problem: Normal B lymphocytes receive signals from B-cell antigen receptor (BCR) that are triggered by binding of the BCR to an external antigen. Tonic signaling through the BCR provides growth and signals to chronic lymphocytic leukemia (CLL) cells, and plays an important role in the pathogenesis and progression of the disease. Antigen engagement of BCR is followed by intracellular recruitment and activation of BCR-associated kinases including spleen tyrosine kinase (Syk), Bruton's tyrosine kinase (Btk) and phosphatidylinositol 3-kinases (PI3K). Inhibition of signaling pathways downstream of the BCR induces disruption of chemokine-mediated CLL cell migration and cell killing. BCR signal transduction inhibitors represent a promising new strategy for targeted CLL treatment. A number of therapeutic agents have recently been developed with significant activity in CLL. The compounds that are currently investigated in patients with CLL include ibrutinib -inhibitor of Btk, fostamatinib-inhibitor of Syk and idelalisib (GS-1101) -a specific isoform of the PI3K (PI3K) inhibitor. The clinical activity of ibrutinib, GS-1101 and fostamatinib in patients with CLL is associated with marked lymphocytosis due to release of tumor cells from the lymph nodes into the peripheral blood. Further studies are ongoing with single agents and their combinations with other targeted and conventional therapies. This article will review the preclinical rationale of BCR signaling inhibitors in the treatment of CLL, and the clinical evidence supporting the use of these agents in CLL patients.
Solution:
What is the name of Bruton's tyrosine kinase inhibitor that can be used for treatment of chronic lymphocytic leukemia?