Among these targets, we have already validated cortactin [3], survivin [4] and TGF-β2 [5] as CD44-positively regulated targets, and further characterized their respective underlying molecular players for each signaling pathway mediating CD44-dependent BC cell survival and motility (CD44/Cortactin, CD44/Survivin and CD44/ TGF-β2). Here, BIRC5 is linked to breast cancer.