CTDSPL2 (CTD Small Phosphatase Like 2) is a protein involved in regulating gene expression by modulating the activity of RNA polymerase II through dephosphorylation. This process affects transcriptional and post-transcriptional control, influencing cell cycle progression and differentiation. Although its precise functions are still being studied, CTDSPL2 plays an important role in cellular growth regulation and may be linked to disease processes such as cancer.