Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
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Question: Context: Chronic myeloid leukemia (CML) arises as a consequence of a chromosomal translocation giving rise to the Philadelphia chromosome and Bcr-Abl oncogene. CML is a clonal disease of stem cell origin and an excellent example of a malignancy in which tumor-initiating cells may hold the key to disease eradication. The known molecular basis of CML has enabled the development of Abl-specific tyrosine kinase inhibitors, such as imatinib mesylate. However, the success of tyrosine kinase inhibitors, as rationally designed first-line therapies, has been tempered by problems of disease persistence and resistance. Residual disease has been shown to be enriched within the stem cell compartment and to persist at stable levels for up to 5 years of complete cytogenetic response. This finding has led to further searches for novel strategies aimed at eliminating these cells; such strategies may be essential in achieving cure. The most significant recent findings are discussed in this review. 
 Question: What tyrosine kinase, involved in a Philadelphia- chromosome positive chronic myelogenous leukemia, is the target of Imatinib (Gleevec)?

Answer: bcr-abl


Question: Context: Christianson syndrome (CS) is an X-linked neurodevelopmental and neurological disorder characterized in males by core symptoms that include non-verbal status, intellectual disability, epilepsy, truncal ataxia, postnatal microcephaly and hyperkinesis. CS is caused by mutations in the SLC9A6 gene, which encodes a multipass transmembrane sodium (potassium)-hydrogen exchanger 6 (NHE6) protein, functional in early recycling endosomes. The extent and variability of the CS phenotype in female heterozygotes, who presumably express the wild-type and mutant SLC9A6 alleles mosaically as a result of X-chromosome inactivation (XCI), have not yet been systematically characterized. Slc9a6 knockout mice (Slc9a6 KO) were generated by insertion of the bacterial lacZ/-galactosidase (-Gal) reporter into exon 6 of the X-linked gene. Mutant Slc9a6 KO male mice have been shown to develop late endosomal/lysosomal dysfunction associated with glycolipid accumulation in selected neuronal populations and patterned degeneration of Purkinje cells (PCs). In heterozygous female Slc9a6 KO mice, -Gal serves as a transcriptional/XCI reporter and thus facilitates testing of effects of mosaic expression of the mutant allele on penetrance of the abnormal phenotype. Using -Gal, we demonstrated mosaic expression of the mutant Slc9a6 allele and mosaically distributed lysosomal glycolipid accumulation and PC pathology in the brains of heterozygous Slc9a6 KO female mice. At the behavioral level, we showed that heterozygous female mice suffer from visuospatial memory and motor coordination deficits similar to but less severe than those observed in X-chromosome hemizygous mutant males. Our studies in heterozygous Slc9a6 KO female mice provide important clues for understanding the likely phenotypic range of Christianson syndrome among females heterozygous for SLC9A6 mutations and might improve diagnostic practice and genetic counseling by helping to characterize this presumably underappreciated patient/carrier group. 
 Question: Mutation of which gene is implicated in the Christianson syndrome?

Answer: slc9a6


Question: Context: Saturday, October 8, 120 miles northeast of Blainsworth, Nebraska; 1:16 p.m.Bob Irisin, a metrologist for the Kansas City weather bureau, is riding in his Bronco truck when he stops and radios to his friend Stan in Kansas City, that he is witnessing a sudden change in weather patterns in the area. Then a tornado suddenly touches down near a farm where Bob sees a family of a man, woman and their little girl standing in front of the house, unaware of the tornado approaching behind them. Bob drives as near as he can go and manages to yell out a warning to the family seconds before they see the twister coming. The family runs into their storm shelter just in time before the twister destroys their house. Bob drives away from harms way just in time.Meanwhile, in Blainsworth, there is the annual fall Bike-a-thon race for the high school kids. 13-year-old Dan Hatch gets a flat tire and doesnt come in at all. Dans stern father, Jack, is arguing with a banker who's asking to foreclose on his hardware shop since a new mall has opened in the nearby town. Jack refuses to sell the shop at any price. Dan walks his bike into the town square where his best friend, Arthur, talks with him about getting "crashed and burned" during the race. Jack walks over and becomes hard on Dan for not finishing the race like a man should. Dan yells at his father for being so demanding and that he can't expect anything from anyone. Dan's mother, Laura, with her new baby Ryan and her friend Jenny, walk by and never less tell him he did okay anyway. Just then, Dan is called to the square podium for he is has been chosen by a lottery to be the winner of a new Schwinn Voyager bicycle, much to his father and mother's delight.75 miles northeast of Blainsworth; 3:37 p.m. Bob sits in his Bronco truck and radios in of rogue weather patterns, while observing another tornado rip through a nearby trailer park. Bob tells Stan that the front is moving south instead of north and the atmospheric activity is the most bizarre he has ever seen. Bob decides to travel to Blainsworth to see if anything will happen.Outside of Blainsworth, Dan and Arthur sit in the woods looking up at the clear sky. Dan tell Arthur about his fathers demanding which is a driving force that he cant stand. Then Arthur's two younger sisters, Stacey and Ronnie Vae, appear and want Arthur to come home since their parents are out of town for the weekend. Arthur and Dan watch as clouds begin to roll in and they decide to get indoors. At Arthurs house, the boys play a game of pool, in which Dan forgets he's suppose to take his grandmother's dog for a walk.Six miles northeast of Blainsworth 4:30 p.m.; Dan arrives at his grandmother Goldie's house where his father is already there taking her dog to the vet, for it has a bad leg. Jack yells at Dan for not being responsible for anything, and Dan rides on his new bike home.Arthur arrives at the Hatch house, were Laura is getting ready to leave for work for the evening. Jenny arrives at the house to pick Laura up, were they talk about Jack being so domineering on Dan for he doesn't want Dan to end up a loser like him.Nightfall. Arthur and Dan play with musical instruments, while checking every few minutes if baby Ryan in the next room is all right. Jack then arrives and tells Dan and Arthur to bring their bicycles in for its raining. Going out, they find that its raining hard and the winds are picking up speed. Arthur tells Dan that since hes originally from Los Angeles, he enjoys the rain, while Dan sees little amusement in it, for he tells Arthur that rain and hailstorms can get bad.At the local diner in town, Laura is waitressing when Bob walks in asking for some coffee. Bob overhears a farmer named Gus talk about the storm and of tornados reported in the area. Bob tells Gus that most people killed by tornados 
 Question: Who does Jack admit he's proud of?

Answer:
dan