Transforming growth factor-beta-stimulated clone-22 (TSC-22) acts as a transcriptionalregulator to modulate cell growth and differentiation and cell death. TSC-22 contains a leucine zipper domain as well as a nuclear export signal, resulting in cytoplasmic localization in living cells. However, concomitant with the induction of apoptosis, TSC-22 translocates from the cytoplasm to the nucleus and shows transcriptional regulatory activity. TSC-22 acts as a major downstream component in the TGF-beta pathway, and also the PPARgamma signalling pathway. The association of these two pathways with tumor suppression, and the significant downregulation of TSC-22 mRNA in various cancer types, such as brain and salivary gland tumors, imply an antiproliferative role for TSC-22.