Abstract Background Genes that escape X-chromosome inactivation (XCI) in female somatic cells vary in number and levels of escape among mammalian species and tissues. potentially contributing to species- and tissue-specific sex differences. CTCF. a master chromatin conformation regulator. https://www.markbroyard.com/great-pick-tablecraft-invertatop-squeeze-bottle-24-oz-translucent-12-pack-cheap-limited-save/