TASK DEFINITION: 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.
PROBLEM: 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?

SOLUTION: slc9a6

PROBLEM: Context: Alejandro Adem is a professor in the Department of Mathematics at the University of British Columbia since 2005 and the holder of a Canada Research Chair at UBC. 
 Question: What is Alejandro Adem's place of employment?

SOLUTION: university of british columbia

PROBLEM: Context: The immune system is the body system that fights to protect the body from specific pathogens. It has a special response for each type of pathogen. The immune systems specific reaction to a pathogen is called an immune response. The immune system is shown in Figure 21.13. It includes several organs and a network of vessels that carry lymph. Lymph is a yellowish liquid that normally leaks out of tiny blood vessels into spaces between cells in tissues. When inflammation occurs, more lymph leaks into tissues, and the lymph is likely to contain pathogens. Immune system organs include bone marrow, the thymus gland, the spleen, and the tonsils. Each organ has a different job in the immune system. Bone marrow is found inside many bones. Its role in the immune system is to produce white blood cells called lymphocytes. The thymus gland is in the chest behind the breast bone. It stores some types of lymphocytes while they mature. The spleen is in the abdomen below the lungs. Its job is to filter pathogens out of the blood. The two tonsils are located on either side of the throat. They trap pathogens that enter the body through the mouth or nose. Lymph vessels make up a circulatory system that is similar to the blood vessels of the cardiovascular system. However, lymph vessels circulate lymph instead of blood, and the heart does not pump lymph through the vessels. Lymph that collects in tissues slowly passes into tiny lymph vessels. Lymph then travels from smaller to larger lymph vessels. Muscles around the lymph vessels contract and squeeze the lymph through the vessels. The lymph vessels also contract to help move the lymph along. Eventually, lymph reaches the main lymph vessels, which are located in the chest. From these vessels, lymph drains into two large veins of the cardiovascular system. This is how lymph returns to the blood. Before lymph reaches the bloodstream, it passes through small oval structures called lymph nodes, which are located along the lymph vessels. Figure 21.14 shows where some of the bodys many lymph nodes are concentrated. Lymph nodes act like filters and remove pathogens from lymph. A lymphocyte is the type of white blood cell involved in an immune system response. You can see what a lymphocyte looks like, greatly magnified, in Figure 21.15. Lymphocytes make up about one quarter of all white blood cells, but there are trillions of them in the human body. Usually, fewer than half of the bodys lymphocytes are in the blood. The majority are in the lymph, lymph nodes, and lymph organs. There are two main types of lymphocytes, called B cells and T cells. Both types of lymphocytes are produced in bone marrow. They are named for the sites where they grow and mature. The B in B cells stands for bone marrow, where B cells mature. The T in T cells stands for thymus gland, where T cells mature. Both B cells and T cells must be switched on in order to fight a specific pathogen. Once this happens, they produce an army of cells that are ready to fight that particular pathogen. How can B and T cells recognize specific pathogens? Pathogens have unique antigens, often located on their cell surface. Antigens are proteins that the body recognizes either as self or nonself. Self antigens include those found on red blood cells that determine a persons blood type. Generally, the immune system doesnt respond to self antigens. Nonself antigens include those found on bacteria, viruses, and other pathogens. Nonself antigens are also found on other cells, such as pollen cells and cancer cells. It is these antigens that trigger an immune response. There are two different types of immune responses. Both types involve lymphocytes. However, one type of response involves B cells. The other type involves T cells. B cells respond to pathogens in the blood and lymph. Most B cells fight infections by making antibodies. An antibody is a large, Y-shaped molecule that binds to an antigen. Each antibody can bind with just one specific type of antigen. The antibody and antigen fit together like a lock and key. You can see how this works in Figure 21.16. The antibody in 
 Question: __type of white blood cell involved in an immune response

SOLUTION:
lymphocyte