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

Example Input: Protein kinases (PKs) and lipid kinases (LKs) are good choices for targets of signal transduction therapy as these enzymes are involved in signaling pathways, and are often related to the pathogenesis of lymphoid malignancies. The attractiveness of PKs and LKs as drug able targets is enhanced by the fact that they are enzymes whose biological activity can be turned off by drugs that block their catalytic site. In the last few years small molecular kinase inhibitors (KIs) have been synthesized and become available for preclinical studies and clinical trials. The first KI, introduced into clinical practice in 1998, was imatinib mesylate, which became the first choice drug in chronic myeloid leukemia. More recently, several KIs have been developed to target the proximal B-cell receptor (BCR) signaling pathway including spleen tyrosine kinase inhibitor (Fostamatinib) and Bruton's tyrosine kinase inhibitors (Ibrutinib, AVL-263). These agents are currently evaluated in early clinical trials in chronic lymphocytic leukemia (CLL) and other diseases. Cyclin-dependent kinase (Cdk) inhibitors, flavopiridol (alvocidib), BMS-387032 (SNS-032), sunitinib and sorafenib are currently under evaluation in clinical trials for relapsed/refractory CLL. Multi-tyrosine kinase inhibitors including vandetanib (ZD6474) bosutinib (SKI-606), TKI258 (CHIR-258), pazopanib (GW786034) and axitinib (AG013736) have been also developed for the treatment of lymphoid malignancies. Phosphatidylinositol 3-kinases (PI3K ) are a family of lipid kinases that mediate signals from cell surface receptors. CAL-101 (GS-1101) is an oral PI3K-specific inhibitor which has shown preclinical and clinical activity against CLL. This article summarizes recent achievements in the mechanism of action, pharmacological properties and clinical activity and toxicity of PK and LK inhibitors in CLL.
Example Output: What is the name of Bruton's tyrosine kinase inhibitor that can be used for treatment of chronic lymphocytic leukemia?

Example Input: Missense mutations in ubiquilin 2 (UBQLN2) cause ALS with frontotemporal dementia (ALS-FTD). Animal models of ALS are useful for understanding the mechanisms of pathogenesis and for preclinical investigations. However, previous rodent models carrying UBQLN2 mutations failed to manifest any sign of motor neuron disease. Here, we show that lines of mice expressing either the ALS-FTD-linked P497S or P506T UBQLN2 mutations have cognitive deficits, shortened lifespans, and develop motor neuron disease, mimicking the human disease. Neuropathologic analysis of the mice with end-stage disease revealed the accumulation of ubiquitinated inclusions in the brain and spinal cord, astrocytosis, a reduction in the number of hippocampal neurons, and reduced staining of TAR-DNA binding protein 43 in the nucleus, with concomitant formation of ubiquitin
Example Output: Which human disease is associated with mutated UBQLN2

Example Input: Young people frequently say that they want to exercise, but they just can't find the time. The solution just might be in-office interval training. Recent studies show that very short but intense exercise rapidly builds and maintains fitness and health, even when the workout is only a few minutes long. Work the stairs You can complete an excellent, effective -- and very brief -- workout in an office stairwell, says Martin Gibala, a professor of kinesiology at McMaster University in Canada and an expert on interval training. For a study that he and his colleagues presented earlier this year, they asked 12 out-of-shape women in their 20s to warm up for two minutes by slowly walking up and down stairs in a campus office building. They completed three of these abbreviated stair workouts per week for six weeks. By the end, their aerobic fitness had improved substantially, the researchers reported, by about as much as if they had been running or cycling each week for hours. Fidget your way to fitness. Parents and teachers may once have urged you to sit still, but wiggling, tapping your toes, standing briefly, and otherwise fidgeting as much as possible at your desk is in fact good for your body. In one recent study, college students showed healthier blood flow in their lower legs if they fidgeted than if they did not. Even better, a 2008 study found that among office workers, those who frequently fidgeted burned as many as 300 calories more each day than those who resolutely stayed still.
Example Output:
How many studies are shown in the passage?