BIRC5 and breast cancer: Considering that survivin, encoded by the BIRC5 gene, is entirely absent in normally differentiated terminal cells [43] and that the transcription initiation site of this gene is believed to be a binding site for the Sp1 complex—a cluster comprising two overlapping putative Sp1 binding sites [44]—it is noteworthy that previous studies have reported the cooperative induction of RhoU small GTPase and a set of atypical WNT response genes by SP1 and STAT3 in breast cancer models, contributing to poor prognosis [45].