The goal of this study is to study NIS expression in benign and malignant breast and thyroid samples using archival formalin-fixed paraffin-embedded tissue sections.

The objective of the study is to further understanding of proteins that occur in both normal cells and tumor cells and to learn more about certain diseases and potential alternative treatments for these diseases.

Inclusion Criteria:

1. Patient must be over the age of 18.
2. Patients must have benign and malignant breast and thyroid cancer.
3. Patient mus sign consent form.

Exclusion Criteria:

1. No children will be allowed.

Cases will be identified from clinic patient medical records and linked to pathology reports. The surgical pathology record number will thus be obtained and used to retrieve the archival blocks and slides. In addition, all these participants will be clinical patients of the Protocol Director, thus the Physician will always be familiar with the participants.