In a recent study on 127 patients, the ORR was significantly higher at 56.5% (TFH phenotype) as compared to 29.4% (non-TFH) [100], supporting prior observations of higher response rates to HDAC inhibitors belinostat, romidepsin and tucidinostat in AITL as compared to PTCL-NOS and ALCL [58, 59, 61–63]. Here, HDAC9 is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.