Project Summary Patient-derived model systems are commonly used to study tumor biology and test novel treatments for head and neck cancer. Our goal is to improve the use of mammalian model systems of head and neck cancer to improve treatment outcomes for patients using valid, predictive, well characterized models. The goal of this supplement is to study cancer evolution and therapeutic response with rigorous assessment of tumor biology and genomic alterations to understand how choices made at the time of establishing models impact their relevance over time. Aim 1 will test the concordance of response between patient-derived models and patients. Aim 2 will investigate the impact of the immune system on tumor evolution. We will use this supplement to support a minority graduate student in the Molecular and Cellular Pharmacology graduate program to study the effect of cisplatin on tumor evolution and the stability of response over multiple passage, to understand how the immune system alters tumor evolution, to provide her with additional training in team science, mentoring, teaching, and communication, and to support her pursuit of an independent research career.