HDAC1 and ovarian neoplasm: R306465 (Figure 1) was identified as potent novel hydroxamate-based inhibitor of histone deacetylase 1 (HDAC1) inhibiting immunoprecipitated HDAC1 complexes in vitro with an IC50 value of 3.3 nM and A2780 ovarian tumour cell proliferation with an IC50 of 39 nM (Table 1).