Histone deacetylases (HDACs) play an important role in maintenance of inactive X chromosome (Xi) and HDAC inhibitors (HDACi) have emerged as a promising new therapeutic strategy for breast and ovarian cancers. However, due to lack of the knowledge on involvement of specific HDAC(s) in Xi maintenance, the HDACi treatment results in several side effects due to the overlapping functions among the HDACs. Furthermore, research has established a link between BRCA1 and XIST (a long non-coding RNA responsible for maintenance of Xi), BRCA1 and HDAC and Xi and hypoacetylation. The present study is aimed at identifying the specific HDAC isoform involved in Xi maintenance and thereby help in designing a treatment strategy involving HDACi specific to the HDAC involved in Xi maintenance and development of female cancers.