SFRP1 and breast cancer: As both c-Myc and c-Jun are notably downstream targets of the canonical and non-canonical Wnt signaling pathways, respectively, which are both down-regulated by Sfrp1, as well as two oncogenes involved in breast cancer progression, we questioned if their expression could also be modulated by parity status, E2, or HA ex vivo, as Sfrp1 was [31,32,33,34].