Correlation of the m/z 28 101 peak with apoA-I and HDL-C assays. The intensities of the m/z 28 101 from all patients with or without PAH peak are plotted against each clinical laboratory measurement of apolipoprotein A-I (apoA-I) and high-density lipoprotein cholesterol (HDL-C) from the same specimens. The Spearman correlation coefficients and P values are indicated.