PP2A interacts with SET-SETBP1 heterodimer but not directly with SETBP1. Cell extracts expressing SETBP1-GFP (lanes 2 and 3) were immunoprecipitated with anti-GFP followed by Western blotting with anti-SET and anti-PP2A. Cell extract without SETBP1-GFP expression was used as negative control (lane 1). One of the cell extracts expressing SETBP1-GFP was precleared of SET using anti-SET antibodies bound to Sepharose-protein G before the immunoprecipitation (lane 2).