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: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited cerebrovascular disease due to mutations involving loss or gain of a cysteine residue in the NOTCH3 gene. A cluster of mutations around exons 3 and 4 was originally reported. Identification of pathogenic mutation is important for diagnostic confirmation of the disease, however genetic counselling and testing of relatives at risk is critical in mutation carriers. Mutation analysis of the NOTCH3 gene was performed through direct sequencing in 140 patients with clinical suspicion of CADASIL. Patients underwent genetic counselling pre and post testing. The 2-23 exons containing all EGF-like domains were screened. 14 familial forms of the disease have been identified with 14 different causative mutations in exons 2, 3, 4, 5, 7, 10, 14, 19, 20 and 22 of the NOTCH3 gene; no pathogenetic mutations have been identified in exons 6 and 8; several genetic variations both in coding as well as in intronic regions were identified too. Our data confirm the importance of screening the whole EGF-like domains region of NOTCH3 gene for the molecular diagnosis of CADASIL among the Italian population too. Moreover genetic variants different from loss or gain of a cysteine residue are identified and presented. 
 Question: Which amino acid residue appears mutated in most of the cases reported with cadasil syndrome?

Answer: cysteine


Question: Context: Rachel (Andrea Bowen), a high school girl, seems to have the life that most people envy: she has a steady boyfriend, some great friends, and a place on the school's soccer team. Preparing for college and separating from her boyfriend are the main worries of this teen, as she lives a carefree life like most girls her age. However, Rachel's world falls apart the day she discovers that Jason (Eric von Detton), a former sexual partner of hers that died an untimely death, was in fact HIV positive and an IV drug user. She immediately goes to an AIDS clinic to get a rapid test, which unfortunately comes back positive. Devastated by the fact that she may actually be infected with the virus, Rachel then confides in her substitute teacher, Sarah (Jennie Garth), who has secretly been living with the disease for years. But both young women are about to find out their secrets will not be kept secret for very long, as word begins to spread throughout their high school and rumors fly, making some of these students realize that they may not be as "clean" as they think they are. 
 Question: What were the results of Rachel's rapid test at the AIDS clinic?

Answer: positive


Question: Context: A personal journey into the heart of the Killing FieldsOne of the most harrowing and compelling personal documentaries of our time, ENEMIES OF THE PEOPLE exposes for the first time the truth about the Killing Fields and the Khmer Rouge who were behind Cambodias horrific genocide. More than simply an inquiry into Cambodias experience, however, ENEMIES OF THE PEOPLE is a profound meditation on the nature of good and evil, shedding light on the capacity of some people to do terrible things and for others to forgive them.Winner of a dozen top documentary festival awards, including a Special Jury Prize at Sundance and the Grand Jury Award at the Full Frame Documentary Festival, this is a riveting film that takes audiences as close to witnessing evil as they are ever likely to get. It is also a personal journey into the heart of darkness by journalist/filmmaker Thet Sambath, whose family was wiped out in the Killing Fields, but whose patience and discipline elicits unprecedented on-camera confessions from perpetrators at all levels of the Khmer Rouge hierarchy. This is investigative journalism of the highest order.In 1974, Thet Sambaths father became one of the nearly two million people who were murdered by the Khmer Rouge when he refused to give them his buffalo. Sambaths mother was forced to marry a Khmer Rouge militiaman and died in childbirth in 1976, while his eldest brother disappeared in 1977. Sambath himself escaped Cambodia at age 10 when the Khmer Rouge fell in 1979.Fast forward to 1998, and Sambath, now a journalist, got to know the children of some senior Khmer Rouge cadre and gradually earned their trust. Then, for a decade, he spent weekends visiting the home of the most senior surviving leader, Nuon Chea, aka Brother Number Two under Pol Pot. But he never used to say anything different from what he told Western journalists, says Sambath, I was low-ranking, I knew nothing, I am not a killer. Then one day he said to me Sambath, I trust you, you are the person I would like to tell my story to. Ask me what you want to know. For the next five years he told me the truth, as he saw it, including all the details of killing.Sambath also won the confidence of lower-level Khmer Rouge soldiers, now ordinary fathers and grandfathers, who demonstrated to him how they slit peoples throats. For these murderers, it was the first time they admitted what they had done. He taped their interactions and discussions about the killings, and together with British documentarian Rob Lemkin they created this landmark film.For Sambath, it has been an ongoing, lifelong personal journey to discover what was behind such horror; he neglected both his family and his own happiness in the search for truth with hope of reconciliation. ENEMIES OF THE PEOPLE is at once a cinematically beautiful, chillingly insightful, and deeply personal piece of documentary filmmaking. 
 Question: How many Cambodians died during the rule of Khmer Rouge?

Answer:
nearly two million