GDNF and neoplasm: In addition, significant increases were observed for GM-CSF (1.8-fold), Timp-1 (8.6-fold) Serpin E1, and tumor growth inducer HB-EGF (2.3-fold), TSP-1 (2.3-fold), GDNF (1.5-fold) in HT-29 TSs cultured with fibroblasts.