S100A9 and Hyperglycemia: Although predominantly expressed in immune cells, expression of S100A8 and S100A9 is increased in activated endothelial cells under conditions of oxidative stress, hyperglycemia, and pro-inflammatory stimuli (McCormick et al., 2005; Sroussi et al., 2009; Yao and Brownlee, 2010; Furman et al., 2019).