CtBP1 is a cellular phosphoprotein that associates with various proteins and functions as a corepressor of transcription. CtBP1 is predominantly localized in the nucleus, where CtBP1 functions as a crucial transcriptional corepressor by interacting with various transcription factors and regulatory proteins to modulate gene expression. This localization is essential for its role in regulating processes such as embryonic development, cell differentiation, and cellular response to DNA damage, thereby maintaining cellular homeostasis and preventing oncogenic transformations. CtBP1 operates in concert with CtBP2 homolog and interacts with proteins like CtIP and BRCA1, highlighting CtBP1′s significance in complex regulatory networks involved in cancer biology and gene silencing. CtBP1′s ability to shuttle between nucleus and cytoplasm under specific cellular conditions underscores CtBP1′s dynamic role in cellular regulation.