Compared with normal and other subtypes of BC, the highest level of BRCA1-IRIS (hereafter IRIS) expression was observed in TNBC, the cellular necrotic/hypoxic/inflammatory centre of IRIS overexpressing (IRISOE) tumors or the vicinity formed an invasive niche, and IL-1β secreted by IRISOE-TNBC cells recruited and activated bone marrow MSCs to secrete CXCL1. Here, IL1B is linked to breast cancer.