This document provides methods and materials involved in assessing cancer (e.g., breast cancer). For example, methods and materials for determining whether or not a cancer patient (e.g., a breast cancer patient) having ER−/PgR−/HER2− cancer cells is likely to have a favorable or unfavorable outcome and/or is likely to respond a cancer treatment that includes a PD-1 inhibitor and/or PD-L1 inhibitor in combination with a JAK2 inhibitor are provided. Methods and materials involved in treating mammals having ER−/PgR−/HER2− cancer (e.g., ER−/PgR−/HER2− breast cancer) by administering a PD-1 inhibitor and/or PD-L1 inhibitor in combination with a JAK2 inhibitor also are provided.
