Expression of 7B2 in normal and unaffected liver compared to colorectal (CRC) liver metastases. A. Quantification of 7B2 mRNA expression respectively, in 3 normal (N), 14 tumor (T) and 14 unaffected (U) liver samples. Quantification was obtained by the ratio of the optical density of 7B2 PCR amplification products over GAPDH. Standard error of mean (SEM) is indicated. Asterisk indicates a statistically significant difference (P < 0.003). B. Schematic representation of 7B2 structure. The furin cleavage site is shown (arrow). The antigenic region against which the antibody was raised is indicated (YAb). C. 7B2 immunoblots in normal liver (N1-N3, top panel), in tumor (T1, T2, bottom panel) and unaffected (U1, U2, bottom panel) liver, indicating presence of 7B2 protein only in tumor. Corresponding gels stained with Coomassie blue G250 (CS) are shown. Experiments were repeated three times.