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. Human monoclonal antibodies HN1 and SD1 targeting mesothelin have been isolated by phage display. Mitchell Ho and Ira Pastan at the U.S. National Institutes of Health (NIH) generated rabbit monoclonal antibodies targeting rare and poorly immunogenic epitopes of mesothelin, including the C terminus recognized by the YP218 antibody. The rabbit antibodies have been humanized by protein engineering and computational structure modeling. The CAR T cells derived from the humanized YP218 antibody (hYP218) effectively inhibit the growth of human xenograft tumors in mice. References Further reading External links Proteins Human proteins