Since IL-6 and IL-8 have been associated with cancer stem cell activation in earlier studies, and their secretion was induced by progranulin treatment in both MCF7 (Figure 1) and MDA-MB-231 cell (Supplementary Figure S2) cultures, we specifically focused on these two cytokines in the further analysis of progranulin-mediated cancer stem cell effects. The gene discussed is CXCL8; the disease is cancer.