Editor’s Note: Cancer prevention and control is a worldwide problem. At present, there are about 3.8 million new cancer cases and 2.29 million deaths in China every year. Among the 15 special actions of Healthy China Action, cancer prevention has attracted much attention. April 15-21, 2020 is the 26th National Cancer Prevention Publicity Week. This year’s publicity theme is "You and I are United on the road to anti-cancer". CCTV and China Anti-Cancer Association launched 7 issues of "Experts Say" series of popular science diagrams, which will help you understand the things that tumors are easily overlooked.

　　CCTV News:Thyroid gland is the largest endocrine organ in human body. It is located right in front of the neck and on both sides of the trachea, shaped like a butterfly. Under normal circumstances, the thyroid gland is homogeneous. If there is a mass in the thyroid gland, it is called thyroid nodule. How to distinguish between benign and malignant thyroid nodules? When should the operation be performed? How to prevent it? Professor Liu Yuewu, Chief Physician of Basic Surgery of Peking Union Medical College Hospital, will give you a detailed answer. (Design: Shi Tianxin)