Inclusion Criteria:

• * Have hormone receptor (HR) positive \[estrogen receptor( ER)+/progesterone receptor (PR)+, ER+/PR- or ER-/PR+)/Her2 negative breast cancer previously diagnosed by biopsy.
• * Have early stage, clinical or anatomic stage I, II or III breast cancer (cT1cN0, cT1cN1, cT2N0, cT2N1, cT3N0)
• * Candidates for intended curative primary resection who have not had neoadjuvant therapy (endocrine/hormonal therapy, chemotherapy with or without immunotherapy).
• * Willing to undergo mandatory intraoperative small excisional and core biopsies (4-6 passes) of tumor and normal tissue for research purposes at the time of proposed surgical resection.

Exclusion Criteria:

• * Is currently enrolled, or will enroll in, a different clinical study in which investigational therapeutic procedures are performed or investigational therapies are administered while participating in this study.
• * Has triple negative (ER-/PR-/Her2-) or HER2+ breast cancer.
• * Concomitant active malignancy
• * Is of child-bearing potential who has not had a recent negative pregnancy test done outside of this clinical trial (i.e., as part of standard preparation for diagnosis and treatment for her cancer)