SKKU) for allowing me to become part of the NTU-SKKU Dual Ph.D. Programme. Moreover, I would like to sincerely thank Prof. Nam-Joon Cho for letting me be part of his research group and for supporting me in every possible way throughout my Ph.D. candidature. His leadership and willingness to encourage his students to do and be their best are truly remarkable. I would also like to thank Prof. Joshua A. Jackman for guiding me through every step of my research from the beginning, not to mention rendering help even with details as minute as planning the experiments, and in the process, bestowing invaluable research skills upon me. His scientific aptitude and passion as well as constant support for young researchers throughout all aspects of professional development are greatly inspiring. Furthermore, I would like to thank Prof. Juha Song and Prof. Jeffrey Glenn for being members of my Thesis Advisory Committee and for helpful advice throughout my studies. I am also grateful to Dr. Bo Kyeong Yoon for teaching me key experimental techniques, Dr. Ferhan Abdul Rahim for giving advice on my qualifying examination preparation, Ms. Soohyun Park for conducting the microscopy experiments related to my project, Mr. Gamaliel Junren Ma for being my closest friend in the group and for having meaningful as well as fun discussions, and all the other group members for always vii being helpful in one way or another. Above all, I would like to thank my Lord and Savior, Jesus Christ, for giving me His abundant grace and peace to walk through life, without which I would not be able to accomplish anything, including Ph.D. studies. viiiTable of Contents Authorship Attribution Statement .