The mechanism of the regulation of Ras degradation revealed in a cover-article in the Journal of Cell Science. ‘A study for the vascularization of embryonic stem cells published in an authoritative journal, Circulation Research Dr. Kang-Yell Choi, professor of the College of Life Science and Biotechnology, identified the mechanism for regulation of the stability of Ras, one of the most famous proto-oncoproteins. This work has been featured as a cover-article of the 122th issue of the Journal of Cell Science which was published in March 4, 2009. The detailed contents of the study also have been introduced in the ‘In This Issue’ section of the journal. Regulation of Ras stability was pioneered by Professor Choi in his previous work which was highlighted as a cover article of the Journal of Biological Chemistry. Soon after publication of the paper, the content of the paper was selected as a "Noteworthy contribution to Scientific Literature" by the Editor of Science, and introduced in the STKE section of ‘Science’ The Ras mutation is one of the most common causes of human cancer, and is found in 30 to 90% of cancer patients. A general and well-accepted view about the Ras regulation holds the exchange of GTP and GDP to be the binding forms of the protein. Ras mutations fixing Ras as the GTP-binding form frequently cause human cancer. Through his series of studies, Professor Choi’s group characterized that the Ras protein can be regulated at the level of protein stability as well by the well-known mechanism of the guanine nucleotides exchange. Moreover, his group confirmed that the regulation of Ras stability related directly with human cancers. Professor Choi proposed applications of his group’s study in the development of new drugs for treatment of osteoporosis and obesity as well as cancer due to the involvement of Wnt signaling in the regulation of Ras stability. The regulation of Ras protein stability can also be applied for production of therapeutic objective cells via differentiation of stem cells. Professor Choi’s research group also has recently reported in an article on the generation of therapeutic vascular endothelial cells from mouse embryonic stem cells. This study was published in the 104th issue of Circulation Research (dated in 27th of February, 2009), an authoritative journal in the cardiovascular field. These studies were supported by the National Research Laboratory (NRL) from the Korea Science and Engineering Foundation (KOSEF). Collaborators of this research include Professors Jon-Bok Yoon and Young-Geun Kwon of the Biochemistry Department and Professors Ho-Geun Kim and Young-Nyun Park of the Pathology Department.