Predicted to enable RNA polymerase II CTD heptapeptide repeat phosphatase activity. Predicted to be involved in protein dephosphorylation. Predicted to act upstream of or within negative regulation of G1/S transition of mitotic cell cycle and negative regulation of protein phosphorylation. Orthologous to human CTDSP2 (CTD small phosphatase 2). [provided by Alliance of Genome Resources, Apr 2022]