sentences:  Circulating mesothelin is reported in nearly all pancreatic cancers, however the levels in healthy persons often exceed 80 ng/mL (using 40 kD molecular weight as the conversion factor) and to widely overlap the values in the pancreatic cancer patients.It was noted that the cutoff levels for normal could differ as much as 10-fold among publications, depending on the assay used and thus that normal levels must be determined anew when new assays are introduced.Increase of mesothelin-specific antibodies were also detected in the sera of about 40% of patients with mesothelioma and 42% with ovarian cancer, indicating an antibody response to mesothelin was correlated with high expression of mesothelin on tumor cells.