IL6 and cancer: In this study, four 6M3SC derivatives (compounds 1, 2, 3 and 4), which have potent anti-cancer activities (CC50 < 50 μM), and one basic 6M3SC compound 0 (Figure 2) [42,44], were selected by 3D pharmacophore similarity analyses to papaverine (3DPFS > 0.4) (Table 1), and examined for their anti-inflammatory activities by HMGB1-stimulated IL-6 production assay using macrophage-like RAW264.7 cells.