IL1B and Stroke: However, once at the lesion site, microglia will also start to proliferate and produce pro-inflammatory cytokines, TNFα, IL-1β, IL-1β, IL-23 and IL-12 [35], and cytotoxic substancse including reactive oxygen intermediates, proteinases and complement proteins, resulting in the exacerbation of the tissue injury and appearance of glia scaring, a major obstacle in functional recovery after stroke [36].