Figure 1: A complicated immune network in colitis-associated cancer (CAC). Previous and current data of CAC in animal models and in man suggest that many cell types as well as soluble factors are involved in the pathogenesis. High levels and continuous production of inflammatory mediators, including cytokines and chemokines by immune cells in lamina propria, may be strongly associated with the pathogenesis of CAC as shown in this figure. Although colonic epithelial cells (CECs) also produce a wide variety of cytokines and chemokines (e.g., IL-8, IL-23, TNFα, TGFβ, KC, MCP-1, and MIP1a) under inflammatory conditions and the following CAC development, these factors in CECs are not indicated here in order to simplify the figure. The abbreviations used in this figure are: Breg, regulatory B cells; Ca, calcium, CCL2, chemokine (C-C motif) ligand 2; CCR2, chemokine (C-C motif) receptor 2; COX-2, cyclooxygenase-2; DC, dendritic cells; EGFR, endothelial growth factor receptor; IGFR, insulin-like growth factor receptor; IL, interleukin; MCP, monocyte-chemoattractant protein; Mϕ, macrophages; NSAIDs, nonsteroidal anti-inflammatory drugs; TGF, transforming growth factor; Th, T helper; TNFR, tumor necrosis factor receptor; Treg, regulatory T cells; CHI3L1, chitinase 3-like-1.