APHA Compound 8 is a potent novel hydroxamate HDAC inhibitor, is in the same structural class as SAHA, an investigational drug standard currently in clinical trial. The IC50 for mouse HDAC1 is 0.5 uM. In a separate study, significant inhibition was found in the proliferation of MEL cells at 24 uM and differentiation, assayed as the accumulation of hemoglobin, at 5 uM.