The novel findings in this study are: 1) Treatment with sirolimus alone lowered expressions of ER and PgR of breast cancer and reduced tumor size; 2) There is no significant difference in ER and PgR expressions between control tumor and Sunitinib treated tumor; 3) Sunitinib treated tumors reduce in diameter after the first treatment, but the diameter increases after the second treatment; 4) Sunitinib treated tumor does not show any aggressive invasive carcinoma of NST histological subtypes; 5) All NMU-induced tumors are HER2/neu-negative scoring. Here, ESR1 is linked to breast cancer.