At this regard, 17-β estradiol stimulates human CC cells growth [61] while tamoxifen, an estrogen antagonist, decreases the proliferation of these cells in vitro and in vivo [61] by stimulating apoptosis through the Fas/APO-1 (CD95) signaling pathway via a calmodulin-dependent mechanism [62]. Here, FAS is linked to cholangiocarcinoma.