TNF and atrial fibrillation: In both NP and AF cells, HMS caused increased secretion of growth-related oncogene (GRO), IL-6, IL-8, IL-15, monocyte chemoattractant protein 1 (MCP-1), MCP-3, monokine induced by γ interferon (MIG), transforming growth factor β1 (TGFβ1) and TNFα.