MMP9 and ovarian cancer: Co-cultured ovarian cancer stem-like cells with macrophages (derived from THP-1 cells) polarized to M2 phenotype increased IL-10, VEGF, MMP-9 and IL-8 secretion, and CD163 and STAT3 expression. THP-1 cell conditioned medium plus IL-8 induced stemness in SKOV3 cells involving IL-8/STAT3 signaling.