Our previous studies have demonstrated that interleukin-1β (IL-1β) stimulated human umbilical cord mesenchymal stem cells (hUCMSCs) increase the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and initiate breast cancer cell apoptosis via ligand to death receptor 4 (DR4) and DR5. This evidence concerns the gene IL1B and breast cancer.