CTDSPL2 (CTD Small Phosphatase Like 2) is a protein involved in regulating gene expression by modulating RNA polymerase II activity through dephosphorylation. This process impacts transcriptional and post-transcriptional control, influencing cell cycle progression and differentiation. While its exact functions are still under investigation, CTDSPL2 plays a key role in regulating cellular growth and may be associated with disease processes such as cancer.