CCL2 and liver dysplastic nodule: For example, after DN onset in db/db mice, delivery of miR-21 knockdown plasmids with ultrasound-microbubble-mediated gene transfer into the diabetic kidneys reduced TNF-α, IL-1β, and MCP-1 in diabetic kidneys, suggesting that miR-21 plays a role in renal inflammation during DN (Zhong et al., 2013).