IL1R2 and breast cancer: A recent study has shown that IL1β derived from primary breast cancer lead to the inhibition of metastasis‐initiating cell colonization in lung, high primary tumor IL1β expression is associated with better overall survival of BC patients.37 However, we demonstrated hypoxia‐inducible IL1β may activate IL1R2 and BTIC self‐renewal in BC tissues, and as reported before,11, 38 high IL1R2 expression indicated a poor prognosis for BC patients.