Local balance of transforming growth factor-β1 secreted from cholangiocarcinoma cells and stromal-derived factor-1 secreted from stromal fibroblasts is a factor involved in invasion of cholangiocarcinoma. - Ohira, Shusaku; Itatsu, Keita; Sasaki, Motoko; Harada, Kenichi; Sato, Yasunori; Yoh Zen; Ishikawa, Akira; Oda, Koji; Nagasaka, Tetsuro; Nimura, Yuji; Nakanuma, Yasuni (Pathology International, 2006)