PTGS2 and skin basal cell carcinoma: In vitro M2-polarized THP-1 macrophages and human monocyte-derived M2 macrophages co-cultured with BCC cells in a transwell system induced COX-2-dependent invasion of cancer cells and angiogenesis by induction of secretion of VEGF-A, bFGF and MMP-9 in BCC cells.