HDAC9 and lymphoma: In addition to hydroxamic acids, other ZBGs such as ortho-aminobenzamides are found in promising HDAC inhibitors (e.g., entinostat, mocetinostat) currently in clinical trials, and the subtype-specific (HDAC1-3 and HDAC10 inhibitor) benzamide tucidinostat (also known as chidamide) has already been locally approved in China and Japan for the therapy of relapsed/refractory (R/R) lymphomas and advanced breast cancer[41,48].