Doxorubicin at 100 nM can induce senescence in MDA-MB-231 breast cancer cells, and the SASPs of the senescent breast cancer cells include interleukin-6 (IL-6), IL-8, matrix metalloprotease-1 (MMP-1), IL-1α, and granulocyte-macrophage colony-stimulating factor (GM-CSF) [23]. This evidence concerns the gene MMP1 and breast cancer.