Eg5 could also be a valid marker in ER+/PR+ BC: again, its pharmacological inhibition demonstrated a reduction in cell viability and proliferation probably correlated with the induction of apoptosis when Eg5 is completely inhibited: In parallel, a role for Eg5 in controlling events not related to mitotic activity, such as migration, invasion, and the occurrence of angiogenesis, was revealed. This evidence concerns the gene PGR and breast cancer.