IL1B and breast cancer: A growing body of research has demonstrated that hypoxic microenvironment drives tumor initiation and progression, and the critical role of hypoxia in tumor‐mediated immunosuppression has also been determined.34 Here we showed that hypoxia induced IL1R2 expression in BC cells and the induced IL1R2 could be further activated by its ligand IL1β, indicating that IL1R2 contributed to the survival and stemness maintenance of BTICs in hypoxic microenvironment.