Involved in mitotic nuclear envelope reassembly by promoting dephosphorylation of BAF/BANF1 during mitotic exit (PubMed:22770216). Coordinates the control of BAF/BANF1 dephosphorylation by inhibiting VRK1 kinase and promoting dephosphorylation of BAF/BANF1 by protein phosphatase 2A (PP2A), thereby facilitating nuclear envelope assembly (PubMed:22770216). May regulate nuclear localization of VRK1 in non-dividing cells (PubMed:31735666). It is unclear whether it acts as a real PP2A regulatory subunit or whether it is involved in recruitment of the PP2A complex (PubMed:22770216). Involved in brain development (PubMed:25259927).