In addition, the synthetic benzamide derivative entinostat (SNDX-275, formerly MS-275) has been found to have selective class I HDAC inhibitory activity and to exert anti-proliferative effects in several tumour models (Saito et al, 1999), with a recommended dose established at 4 mg m−2 given weekly for 3 weeks every 28 days or at 2–6 mg m−2 given once every other week (Gore et al, 2008). This evidence concerns the gene HDAC9 and neoplasm.