In a multivariate linear regression model including all observations, only the degree of uremia as indicated by serum urea levels was an independent significant predictor of microvascular density (p < 0.0001), whereas all other variables correlating with density in univariate regression, i.e. hematocrit (p = 0.990), weight change (p = 0.220), IL-6 (p = 0.157) and MAP (p = 0.245), were excluded from the model (corrected r2 = 0.502). The gene discussed is IL6; the disease is uremia.