Adjusted mean ± SE concentrations of the products or metabolites of selected HIF-1–regulated genes according to VHL 598C>T genotype in persons of Chuvash ethnicity. (A) Serum VEGF analysis of variance (ANOVA) model with adjustment for peripheral blood platelet count. (B) Serum nitrite/nitrate, stable end products of nitric oxide breakdown. (C) Serum PAI-1 ANOVA model with adjustment for peripheral blood platelet count. (D) Serum erythropoietin (EPO) ANOVA model with adjustment for sex and hemoglobin concentration. (E) Serum transferrin receptor ANOVA model with adjustment for serum ferritin concentration. The numbers of subjects for each genotype category are as indicated in Table 2. The P value represents the significance level for the overall ANOVA and also for the comparison of unaffected participants with VHL 598C>T homozygotes. Only for PAI-1 was there a significant difference between unaffected participants and VHL 598C>T heterozygotes, and this was at the .03 significance level.