TINP1 (TGF beta inducible nuclear protein 1) was widely expressed in various cell lines. TINP1 overexpression significantly promoted tumor cell proliferation,which may be associated with the downregulation of p53 expression. Furthermore,TINP1 promoted a number of cell lines to the S phase of the cell cycle. TINP1 promotes cell proliferation and significantly reduces p53 and p21 expression.