A Major Research Breakthrough, Published in the 'Proceedings of the National Academy of Sciences (PNAS) The secrets about the body parts of mammals such as the limbs and the lacteal gland have been revealed. Professor Jung Han-Sung from the College of Dentistry, and researchers Kim Jae-Young and Jo Gyoung-Won, presented that the back, the stomach, and the limbs, as well as other organs are formed through the interaction between genes in a cell. The research team declared that "Once the axis of the back and the stomach is formed through the interaction between two genes (Tbx3 and Bmp4) in a cell, this defines the locations for the arms, legs, and the lacteal gland of the body." This research was supported by the Research Center for Orofacial Hard Tissue Regeneration (MRC) of the Korea Science and Engineering Foundation, and the research findings entitled "Molecular interactions between Tbx3 and Bmp4 and a model for dorsoventral positioning of mammary gland development" were printed in the November issue of Proceedings of the National Academy of Sciences of the United States of America (PNAS), a world-renowned medical science journal. Professor Jung researched mice embryos to observe the process of production. After the observation, he concluded that the "relationship of push-and-pull dynamics" between the two genes, called Tbx3, which helps in formulating the back of the body, and Bmp4, which assists in creating the stomach area, forms the location of the limbs and breasts. The study of biological development had thus far been limited to figuring out the formation of the abdomen of 2-dimensional protozoan with up-down-left-right axis. Therefore, the work of Professor Jung and his team is significant for it is the first achievement in the world which explains the gene determining the border of the abdomen and back by focusing on the development of mammals with 3-dimensional figures. This research seems to assist the study of evolution by identifying that the unique hair border on the body, which is used to confirm a mammal's class, is also determined by Tbx3 and Bmp4. Also the research team is expecting this investigation to present us with important information related to the cure of rare congenital genetic disorders such as UMS (Ulnar Mammary Syndrome), which is a disease in which a person is born with limbs and breasts located near the back area and has problems with the formation of ulnars on the little finger and the arms.