ADAM17 and Stroke: Expectedly, ADAM17 mRNA expression, CD163 mRNA expression, cellular TACE activity, and sCD163 levels were significantly positively correlated across the collective patient population, allowing us to summarize the peripheral activity of the sCD163 production pathway in terms of a single composite variable using principal components analysis (Fig. 1E); this composite variable was positively associated with injury severity in terms of both the National Institutes of Health stroke scale (NIHSS) and infarct volume (Fig. 1F,G).