Activation of Class I HDACs (HDACs 1, 2, 3, and 8) and Class IIb HDACs (HDAC6) are thought to promote pathological hypertrophy, whereas class II HDACs (HDACs 4, 5, 7, and 9) are thought to suppress cardiac hypertrophy. The gene discussed is HDAC6; the disease is cardiac hypertrophy.