MMP9 and infection: In vitro infection of murine microglia cell line (BV2) with DENV 1–4 resulted in increased expression of proinflammatory cytokines, including TNF-α, IFN-γ, IL-1β and IL-10, MCP-1, and IL-6, and of MMP-2 and MMP-9 (Bhatt et al., 2015).