Since cholesterol trafficking is also influenced by STARD3, a late endosomal START (StAR-related lipid transfer) domain protein with considerable homology to COOH-terminal StAR that was cloned initially in HER2+ BC [51,52], the potential modification(s) of STARD3, modulating E2 biosynthesis in breast tissue, cannot be excluded. This evidence concerns the gene ERBB2 and breast cancer.