We previously demonstrated that IGFBP‐3 and TGF‐β inhibit growth in epithelial cells by stimulating TβR‐V‐mediated tumor suppressor signaling which involves IRS‐1/2‐dependent activation and cytoplasm‐to‐nucleus translocation of IGFBP‐3‐ or TGF‐β‐stimulated protein phosphatase (PPase), and dephosphorylation of retinoblastoma family proteins in the nucleus, resulting in cell growth arrest.7, 10, 22, 23. Here, PPA1 is linked to neoplasm.