For example, (1) miR-92a and cluster member miR-18a block angiogenesis when overexpressed in endothelial cells (Bonauer et al., 2009; Doebele et al., 2010), (2) increased miR-92a in plasma levels in patients with traumatic brain injury (TBI) is a good biomarker for the severity of the disease (Redell et al., 2010), and (3) family member miR-92b is involved in synaptic signaling (Ceman and Saugstad, 2011). These diverse functions provide evidence for versatile and complex systemic roles of miRNAs.
