Editorial to the 4^th Ruijin International Thoracic Symposium (RITS 2019)—Special Issue

The 4^th Ruijin International Thoracic Symposium (RITS 2019) and the 4^th Huaxia Thoracic Surgery Medical Forum organized by Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine took place successfully in Shanghai from July 19^th to 20^th 2019. This symposium gathered many leading experts in the field of thoracic surgery all over the world to conduct extensive exchanges on hot topics of thoracic surgery, and more than 350 participants attended the course.