Abstract: This document provides methods and materials involved in assessing chemotherapy responsiveness and treating cancer (e.g., breast cancer). For example, methods and materials for determining whether or not a cancer patient (e.g., a breast cancer patient) is likely to respond to chemotherapy (e.g., a taxane therapy) based at least in part on the presence of a variant in the mammal's polycystic kidney disease gene 1 (PKD1) are provided. In addition, methods and materials involved in treating mammals having cancer (e.g., breast cancer) by administering an inhibitor of ubiquitin specific peptidase 2 (USP2) polypeptide activity (e.g., NSC-632839, a 2-cyano-pyrimidine, or a 2-cyano-triazine) in combination with another chemotherapeutic agent such as a taxane therapy are provided.

Abstract: This document provides methods and materials involved in assessing chemotherapy responsiveness and treating cancer (e.g., breast cancer). For example, methods and materials for determining whether or not a cancer patient (e.g., a breast cancer patient) is likely to respond to chemotherapy (e.g., a taxane therapy) based at least in part on the presence of a variant in the mammal's polycystic kidney disease gene 1 (PKD1) are provided. In addition, methods and materials involved in treating mammals having cancer (e.g., breast cancer) by administering an inhibitor of ubiquitin specific peptidase 2 (USP2) polypeptide activity (e.g., NSC-632839, a 2-cyano-pyrimidine, or a 2-cyano-triazine) in combination with another chemotherapeutic agent such as a taxane therapy are provided.