Despite expectations from previous studies of contextual fear conditioning using the HDAC inhibitor phenylbutyrate in Tg2576 mice [31], or using various HDAC inhibitors including SAHA in double transgenic AD model mice (over-expressing the same ‘swedish’ mutant APP as the Tg2576 mice as well as mutant presenilin 1) [30], we did not observe a significant rescue of contextual fear conditioning in Tg2576 mice treated with 25 mg/kg or 50 mg/kg SAHA. The gene discussed is HDAC9; the disease is Alzheimer disease.