Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
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Question: In this phase 2 proof-of-concept study we examined the safety and efficacy of selexipag, an orally available, selective prostacyclin receptor (IP receptor) agonist, as a treatment for pulmonary arterial hypertension (PAH). 43 adult patients with symptomatic PAH (receiving stable endothelin receptor antagonist and/or a phosphodiesterase type-5 inhibitor therapy) were randomised three to one to receive either selexipag or placebo. Dosage was up-titrated in 200-g increments from 200 g twice daily on day 1 to the maximum tolerated dose by day 35 (maximum allowed dose of 800 g twice daily). Change in pulmonary vascular resistance at week 17 expressed as a percentage of the baseline value was the primary efficacy end-point, and was analysed in the per protocol set first and then in the all-treated set to assess robustness of results. A statistically significant 30.3% reduction in geometric mean pulmonary vascular resistance was observed after 17 weeks' treatment with selexipag compared with placebo (95% confidence limits -44.7- -12.2; p=0.0045, Wilcoxon rank sum test). This was supported by a similar result from the all-treated set. Selexipag was well tolerated with a safety profile in line with the expected pharmacological effect. Our results encourage the further investigation of selexipag for the treatment of PAH.

Answer: Selexipag is used for which disease?


Question: C.D. "Charlie" Bales, the fire chief of the small American ski town of Nelson, Washington, is intelligent, humorous, charismatic, athletic and skilled. Bales is sensitive about his large nose, which many in town have learned to not mention. He is unable to have it surgically altered because of a dangerous allergy to anesthetics. He is close to many in town, especially his godsister, Dixie, who owns the town diner and several rental homes. He becomes immediately attracted to beautiful newcomer Roxanne Kowalski, an astronomy student renting from Dixie while searching for a new comet. She adores Bales, but only as a friend, preferring Chris, a handsome but dim fireman. Roxanne goes to Bales for help when Chris fails to advance their relationship further than curious glances. Through a turn of events, she falsely believes Chris is deeply intelligent. When Bales informs Chris of Roxanne's interest, Chris gets sick, intimidated by intelligent women. Chris starts to write her a letter, but takes all day with little result. He convinces Bales to write the letter, with prose that soon bowls over Roxanne. When informed that Roxanne wants to meet him, Chris again gets sick and refuses to meet until Bales comes up with a plan to allow him to be as brilliant as his letter makes him appear. Chris arrives at Roxanne's house with a hunter's cap on, hiding the earphones that relay Bales' words. When the equipment fails, Chris bungles the meeting by speaking his own crass thoughts. After Roxanne storms back into the house furious, Chris begs Bales to fix his mess again. At first he repeats what he is told from under a tree beneath Roxanne's window, but soon also ruins that. Then they switch jackets and hats so Bales can speak the words as Chris. They achieve their goal, and she invites Chris in to make love. Roxanne gets word about the comet and has to go out of town for a week. Since she can't find Chris, she gives Bales the address of her hotel and asks him to tell Chris to write to her. Bales writes her several times a day, each letter more incredible than the last. They affect Roxanne so deeply that she returns early. Bales is writing a new letter to her in Dixie's diner when he finds out that Chris (who knows nothing about the letters) is on his way to see Roxanne. He arrives at her home and warns Chris that Roxanne would be mentioning some letters that he supposedly wrote. She tries to get Chris to be the man in the letters, revealing that his looks are only secondary to her. Knowing that his looks are all he has, Chris runs out, leaving her confused. Dixie puts the last letter under her door and after reading it, Roxanne calls Bales over. Chris prepares to leave town with a bartender, Sandy, whom he met while Roxanne was away. When she asks if he has told Roxanne (the women are acquaintances), he replies that he will write her a letter since he has a history of it. Bales arrives, unaware that Roxanne knows the truth. She asks him to read one of the letters and then to look at the back, which shows that Dixie revealed its true author. She explodes in anger that he lied to her. He retorts that he simply wanted to tell her how he felt about her, but she was only interested in Chris's face and body. When he reminds her that it only took a few nice words for Chris to get her into bed, she punches him in the face and throws him out. As he prepares to say more he stops and sniffs the air. He slowly walks back to the firehouse and alerts his team, who then "follow his nose" until they find and extinguish the fire. During their celebration afterwards, someone mentions his nose and although everyone thinks he will get upset, he doesn't. Back home, sitting on his roof, Bales hears someone speaking his words to him. It's Roxanne, declaring that she realizes that it was everything from Bales that she loved, not Chris'

Answer: Who is C.D.'s god-sister?


Question: Iron deficiency is a frequent side effect of blood donation. In recent years, several studies have described genetic variants associated with iron concentrations. However, the impact of these variants on iron levels is unknown in blood donors. Knowledge of genetic variants that predispose donors to iron deficiency would allow bleeding frequency and iron supplementation to be tailored to the individual donor. The genotypes of five specific single-nucleotide polymorphisms (SNPs) in three genes that have been previously associated with iron status and/or restless leg syndrome (RLS) were investigated in two groups of female blood donors. The first group had low iron stores (serum ferritin 12g/L, n=657), and the second group had normal to high iron stores (serum ferritin > 30g/L, n=645). Genotype distribution for each of the SNPs was compared between the two groups. Homozygosity for the T-allele of BTBD9 rs9296249 was associated with lower serum ferritin. The odds ratio for low serum ferritin was 1.35 (95% confidence interval, 1.02-1.77; p=0.03) when comparing donors with the TT genotype with donors with the CT genotype. A frequent polymorphism in BTBD9 was significantly associated with serum ferritin. This polymorphism has previously been associated with RLS, but not low iron stores in blood donors.

Answer:
Which deficiency is the cause of restless leg syndrome?