Quantification of serum mesothelin. (A) Correlation between the quantification of serum mesothelin by SRM assay technology (peptide KWDVTSLETLK) or by ELISA (Mesomark®) among 75 subjects (23 MPM = red dots, 26 HD = blue dots, 26 NSCLC = green dots) (Additional file 3: Table S2). Reported is the Spearman’s rank correlation coefficient (P < 0.05 is considered significant). Dashed line denotes best fit as calculated by linear regression (y = 8.1 + 0.82x). (B) Serum levels of mesothelin assessed by ELISA (Mesomark®) or by SRM assay technology (peptide KWDVTSLETLK) in the groups of MPM, HD and NSCLC of the 75 subjects (23 MPM, 26 HD, 26 NSCLC) (Additional file 3: Table S2). Significant differences of mean levels between the groups are assessed using the Mann-Whithney test. P-values are two-tailed and considered significant if < 0.05. Boxes report 25th and 75th percentile. Crosses inside the boxes indicate means and lines indicate medians. Whiskers indicate minimal and maximal values.