TARSH [ABI family, member 3 (NESH) binding protein], whose alternative names include target of Nesh-SH3, Nesh-binding protein, ABI gene family member 3-binding protein, NESHBP, FLJ41743, FLJ41754 or ABI3BP, is a 1,075 amino acid protein involved in cellular senescence and tumor suppression. Loss of TARSH expression may play a role in the pathogenesis of cancer, especially in thyroid and lung. TARSH acts as a signal transduction molecule and is presumed to interact with with Abi-3, a protein involved in inhibition of ectopic metastasis of tumor cells. TARSH is expressed in brain, lung, heart, liver, placenta, pancreas and kidney, and four TARSH isoforms exist as a result of alternative splicing. TARSH contains a SH3 binding motif and a nuclear targeting sequence.