Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Example Input: Selenoproteins are proteins containing an uncommon amino acid selenocysteine (Sec). Sec is inserted by a specific translational machinery that recognizes a stem-loop structure, the SECIS element, at the 3' UTR of selenoprotein genes and recodes a UGA codon within the coding sequence. As UGA is normally a translational stop signal, selenoproteins are generally misannotated and designated tools have to be developed for this class of proteins. Here, we present two new computational methods for selenoprotein identification and analysis, which we provide publicly through the web servers at [Link] or [Link] SECISearch3 replaces its predecessor SECISearch as a tool for prediction of eukaryotic SECIS elements. Seblastian is a new method for selenoprotein gene detection that uses SECISearch3 and then predicts selenoprotein sequences encoded upstream of SECIS elements. Seblastian is able to both identify known selenoproteins and predict new selenoproteins. By applying these tools to diverse eukaryotic genomes, we provide a ranked list of newly predicted selenoproteins together with their annotated cysteine-containing homologues. An analysis of a representative candidate belonging to the AhpC family shows how the use of Sec in this protein evolved in bacterial and eukaryotic lineages.
Example Output: What is the name of the stem loop present in the 3' end of genes encoding for selenoproteins?

Example Input: Zach Conroy and Celeste Mercier are the hottest couple on and off the ice until a nasty spill knocks Celeste out of competition. With their dreams of gold medals put in ice and their romance chilling as a result, Zach has to find another partner for the championship in Paris. And fast. In glides Alejandra Alex Delgado, a beautiful, tough talking hockey player with fierce moves and a fearless skating style. Zachs willing to give her a chance, but his coach, Bryan quits in a huff to train Zachs biggest rivals, Cindy Halgyord and Jason Bright. That leaves Zach with a newbie partner and no coach until he convinces former figure skating champ Jackie Dorsey to step in. She puts Zach and Alex through their paces, but the hardest trick of all is keeping them focused on practice and not each other as they bicker and struggle with a growing attraction both on and off the ice. Jackie knows these kids are fire and ice, and sees the chemistry between them. She also knows that if they cant get it together, theyll set the skating world on fire. That is, if the heat between them doesnt cause a total meltdown. With the competition fierce and the stakes higher than ever, the only way Zach and Alex can win is by putting aside their feelings and pulling out a secret weapon: the deadly Pamchecko jump. But is it worth the risk? Can Zach rise above the past and his history of injuring partners? And can Alex prove that shes got the moves to match her passion? It all comes down to the biggest moment of their lives when they learn that sometimes on the ice and in life youve got to risk it all.
Example Output: Who refuses to coach the pair?

Example Input: Activating point mutations in the K-Ras oncogene are among the most common genetic alterations in pancreatic cancer, occurring early in the progression of the disease. However, the function of mutant K-Ras activity in tumor angiogenesis remains poorly understood. Using human pancreatic duct epithelial (HPDE) and K-Ras4B(G12V)-transformed HPDE (HPDE-KRas) cells, we show that activated K-Ras significantly enhanced the production of angiogenic factors including CXC chemokines and vascular endothelial growth factor (VEGF). Western blot analysis revealed that K-Ras activation promoted the phosphorylation of Raf/mitogen-activated protein kinase kinase-1/2 (MEK1/2) and expression of c-Jun. MEK1/2 inhibitors, U0126 and PD98059, significantly inhibited the secretion of both CXC chemokines and VEGF, whereas the c-Jun NH(2)-terminal kinase inhibitor SP600125 abrogated only CXC chemokine production. To further elucidate the biological functions of oncogenic K-Ras in promoting angiogenesis, we did in vitro invasion and tube formation assays using human umbilical vein endothelial cells (HUVEC). HUVEC cocultured with HPDE-KRas showed significantly enhanced invasiveness and tube formation as compared with either control (without coculture) or coculture with HPDE. Moreover, SB225002 (a CXCR2 inhibitor) and 2C3 (an anti-VEGF monoclonal antibody) either alone or in a cooperative manner significantly reduced the degree of both Ras-dependent HUVEC invasiveness and tube formation. Similar results were obtained using another pair of immortalized human pancreatic duct-derived cells, E6/E7/st and its oncogenic K-Ras variant, E6/E7/Ras/st. Taken together, our results suggest that angiogenesis is initiated by paracrine epithelial secretion of CXC chemokines and VEGF downstream of activated oncogenic K-Ras, and that this vascular maturation is in part dependent on MEK1/2 and c-Jun signaling.
Example Output:
Which is the molecular mechanism underlying K-ras alterations in carcinomas?