Dr. Timotius Ivan Hariyanto is a Clinician, Scientist, and Researcher from the Faculty of Medicine, Pelita Harapan University, Indonesia. He has received his BMed degree from Pelita Harapan University in 2017 and then received his Medical Doctor (MD) degree from Pelita Harapan University in 2020. He has been a researcher, statistician, and assistant Professor in the Department of Internal Medicine, Faculty of Medicine Pelita Harapan University - Siloam Hospitals Lippo Village since 2020. He has been serving as Guest Editor in Frontiers in Nutrition on the year 2021-2022 for the Research Topic "Dyslipidemia, Obesity, and coronavirus disease 2019", a reviewer in several scientific journals such as Heliyon, PLOS ONE, Scientific Reports, Reviews in Medical Virology, Frontiers in Medicine, and etc (a total of more than 200 verified reviews). Currently, he serves as the Editor-in-Chief in World Journal of Methodology, Academic Editor in PLOS ONE, and Advisory Board member in Heliyon - section Infectious Diseases. He also has published more than 50 peer-reviewed articles with 1900 + + citations in Google Scholar. Currently he is an active member of Cochrane Collaborations, European Society of Medical Oncology (ESMO), and European Society of Endocrinology (ESE). He also works in the Emergency Department of Tidar General Hospital and Siloam Hospitals Yogyakarta. His ongoing research interests are internal medicine, research methodology, systematic review and meta-analysis, experimental study, cohort study, endocrinology, and infectious diseases.