During apoptosis induced by ESC-3, an active ingredient of crocodile bile, in human cholangiocarcinoma Mz-ChA-1 cells, PHB1 is dramatically downregulated, and the region of co-localization between PHB1 and AIF, p53, Rb, and c-fos shifted from the cytoplasm to the nucleus. This evidence concerns the gene PHB1 and cholangiocarcinoma.