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Updated: Apr 4, 2026

Heterogeneity Mapping of Protein Expression in Tumors using Quantitative Immunofluorescence
Published on: October 25, 2011
Biological variations of seven tumor markers
Zhihong Qi1, Lin Zhang1, Yu Chen1
1Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.
Background:
We sought to identify biological variations in the following tumor markers: pepsinogen I (PGI), pepsinogen II (PGII), carbohydrate antigen 724 (CA724), neuron-specific enolase (NSE), pro-gastrin-releasing peptide (ProGRP), carcinoembryonic antigen (CEA), and carbohydrate antigen 199 (CA199).
Methods:
Serum samples were collected from 20 healthy Chinese individuals over 5 days. Samples were then screened for the presence of the seven aforementioned tumor markers. Within-individual coefficient of variation (CVI), between-individual coefficient of variation (CVG), confidence interval (CI) of biological variations, index of individuality (II), and the reference change value (RCV) of the seven tumor markers were calculated.
Results:
Of the 7 tumor markers, index of individuality was all <1.0. ProGRP showed the lowest CVI and CVG, at 4.75% (CI: 3.96%-5.94%) and 16.42% (CI: 12.32%-24.61%), respectively. The 95% and 99% RCVs for ProGRP were 14.68 and 19.32, respectively, and were the lowest of the markers. In contrast, the CVI and CVG for CA724 were the highest, at 16.06% (CI: 13.83%-19.17%) and 96.95% (CI: 73.73%-141.59%), respectively. The 95% and 99% RCVs for CA724 were the highest, at 45.89 and 60.41, respectively.
Conclusion:
Our findings provide additional information regarding the biological variation of tumor markers, and could be applied in a clinical setting.

