Both IL-8 antibody and CXCR1/CXCR2 antibody combination significantly reduced the sphere number and size of G9a-overexpressing cells indicating that IL-8 is a mediator for G9a to promote cancer stemness via an IL-8/CXCR1/2 signaling axis (Supplementary Figure S3). Here, CXCL8 is linked to cancer.