As effects of similar matrices on gene expression have been reported previously [39], the decreased migration of U87 cells in indirect co-culture with U373 cells might result from increased expression of the C1qTnf5 (C1q and tumor necrosis factor related protein 5) gene, which enhances adhesion of retinal epithelial cells [40], and decreased expression of the Plod2 (Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2) gene, which inhibits sarcoma cell migration [39]. The gene discussed is PLOD2; the disease is sarcoma.