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.

Example Input: Context: Mutations of SLC9A6 may cause an X-linked clinical syndrome first described by Christianson in 1999 in which affected males exhibited profound intellectual disability, autism, drug-resistant epilepsy, ophthalmoplegia, mild craniofacial dysmorphism, microcephaly, and ataxia. We describe a child with an SLC9A6 mutation and an electroencephalographic pattern consistent with electrographic status epilepticus of sleep. Our patient's electrographic status epilepticus of sleep resolved after treatment with felbamate. Following treatment, he remained seizure-free but did not make significant or lasting gains in language. Our report extends the clinical epilepsy phenotype in children with SLC9A6 mutations to include electrographic status epilepticus of sleep. In addition, felbamate was an effective treatment for electrographic status epilepticus of sleep in our patient. 
 Question: Mutation of which gene is implicated in the Christianson syndrome?
Example Output: slc9a6

Example Input: Context: Reactive oxygen species are involved in ovulation. The aim of this study was to examine gonadotropin regulation of antioxidant enzyme sulfiredoxin (Srx) and peroxiredoxin 2 (PRDX2) expressions and modification during the ovulatory process in rats. Administration of antioxidants in vivo reduced ovulation rate and cumulus expansion. LH treatment increased H(2)O(2) levels within 15 min, which, in turn, induced Srx gene expression in cultured preovulatory follicles. Treatment of preovulatory follicles with catalase suppressed the stimulatory effect of LH on Akt phosphorylation. LH- or H(2)O(2)-stimulated Srx mRNA levels were suppressed by inhibitors of antioxidant agents and MAPK kinase. An in vivo injection of equine chorionic gonadotropin-human chorionic gonadotropin (hCG) stimulated Srx mRNA within 1 h in granulosa but not thecal cells of preovulatory follicles. Srx protein levels were stimulated from 3 h post-hCG injection. Immunofluorescence analysis revealed that oocytes expressed the Srx protein. Furthermore, hCG treatment increased Srx expression in mural granulosa, theca and cumulus cells, but the Srx protein was not detected in corpora lutea. Gene expression of PRDX2, identified as an Srx-dependent modified enzyme, was stimulated by gonadotropins. In situ hybridization analysis demonstrated that PRDX2 mRNA was detected in oocytes and theca cells as well as granulosa cells of some antral and preovulatory follicles. High levels of PRDX2 mRNA were detected in corpora lutea. Total levels of PRDX2 protein were not changed by gonadotropins. However, levels of hyperoxidized PRDX2 increased within 2-3 h after the hCG injection. Taken together, gonadotropin stimulation of Srx expression and PRDX2 modification in the ovary suggest the existence of an antioxidant system to maintain H(2)O(2) production and elimination during the periovulatory period. 
 Question: What type of enzyme is peroxiredoxin 2 (PRDX2)?
Example Output: antioxidant

Example Input: Context: The story is not linked to the first part of the series. Instead, it focuses on a fictional explanation for the Ryanggang explosion in 2004, in which an unexplained mushroom cloud occurred in North Korea. After reconnaissance satellites detect a large, three-stage Topol intercontinental ballistic missile carrying a nuclear weapon in North Korea, which can strike anywhere in the continental United States, a fictional United States President Adair T. Manning (Peter Coyote) orders a team of U.S. Navy SEALs to destroy the missile and the launch site. The team is led by Lieutenant Robert James (Nicholas Gonzalez). The Pentagon aborts the mission after it receives new information, but by the time the abort order is sent, two SEALs have already parachuted into North Korean territory. James stops the third SEAL from deploying, accidentally knocking the man's helmet against the status indicator mounted near the door. The lieutenant steps onto the makeshift ramp to peer outside, returning to the doorway to inform the rest of men of the abort. The high-speed winds from outside rip the indicator loose and send it flying into the lieutenant's face. Stumbling backwards, James loses his balance and is sucked out of the plane. Callaghan disobeys orders to stand fast, strikes his commanding officer, and follows the first three, taking a radio with him. When North Korean forces led by Commander Hwang (Joseph Steven Yang) find the SEALs, two of the Navy SEALs are killed in a gun battle, and James and Callaghan are captured and tortured by Hwang and his men. After South Korean special forces rescue James and Callaghan, President Manning and the South Korean government send the SEALs and South Korean special forces to destroy the missile site. But after losing radio contact with the SEALs, the President and his top advisers believe that they have been captured again. Under pressure from his military advisor, General Norman Vance (Bruce McGill), the President decides to send B-2 stealth bombers to destroy the site, which would start a full-scale war against North Korea. The SEALs and the South Korean special forces are almost recaptured by Hwang, but he is shot by a defecting officer. James and the South Koreans destroy the missile silo with a bomb before the bombers reach the missile site, which averts the bombing and prevents a full-scale war. A tribunal convicts Callaghan of striking an officer (1 year) and disobeying an officer (10 years). Due to the "black op" nature of the mission, the transcript of the hearing is deemed classified and the charges are expunged from his record, leaving him free to return to his family. Meanwhile, James meets the president in a classified meeting, bringing his mentor Master Chief Scott Boytano (Keith David) as witness to James' receiving of an award. The film closes with Boytano telling James he wasn't red flagged because Boytano had never seen anyone who desired so badly as James did to be a SEAL. During the credits there is a news report on the Ryanggang explosion. 
 Question: Who rescues James and Callaghan?
Example Output:
south korean special forces