HDAC9 and thyroid cancer: CUDC-907, a dual PI3K/HDAC inhibitor, has been proposed to have therapeutic potential in many hematopoietic malignancies and solid cancers, such as chronic lymphocytic leukemia, acute myeloid leukemia, thyroid cancer, and pancreatic adenocarcinoma (Kotian et al., 2017; Chen et al., 2019b; Fu et al., 2019; Li et al., 2019).