HDAC6 and ductal breast carcinoma in situ: For example, a study of 58 breast samples found that levels of acetylated histone H4, H4K12ac, and acetylated tubulin, as well as the histone deacetylases HDAC1, HDAC2, and HDAC6, were significantly lower in ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) compared to normal mammary epithelium (22).