HDAC2 and early-onset autosomal dominant Alzheimer disease: Histone deacetylases (HDACs) control the gene expression and cellular signaling and histone deacetylases 2 (HDAC2) is overexpressed in solid tumors including colon cancer, lung cancer, cervical carcinoma, breast cancer, and kidney/cervix cancer and also in Alzheimer's disease [9, 10].