Production of VEGF by RMG-1 cells was only mildly suppressed by anti-IL-6 antibody treatment as evidenced by ELISA analysis of culture supernatant (Fig. 3A), whereas osteopontin production by RMG-1 tumor cells was significantly suppressed by anti-IL-6 (p < 0.01) (Fig. 3B). Here, SPP1 is linked to neoplasm.