Cells were pre-treated with PKC inhibitors (chelerythrine, Fig. 2A; H-7, Fig. 2B) or a calcium signaling inhibitor (2-APB, Fig. 2C) overnight followed by 5 μM MeHg (without the testing agent) overnight, and then IL-6 production and cell viability were determined. Results indicated that PKC inhibition had little effect on IL-6 release. In contrast, prevention of calcium signaling could significantly reduce IL-6 release. See text for more discussion on this issue.