BMC Cancer 2008, 8:270 http://www.biomedcentral.com/1471-2407/8/270 VFaigliudarteio8n of the gene-array analysis Validation of the gene-array analysis. Expression of selected genes in the mammary gland of aged multiparous mice and tumors was analyzed by semi-quantitative RT-PCR. After blotting and hybridization to the relevant probes, signals (on the left) were quantitated and their average intensities ± SEM are presented (Middle panels). The relative expressions of the individual genes in the carcinoma vs. papillary adenocarcinoma were calculated and compared to those obtained from the microarray data (right panels). Page 15 of 19 (page number not for citation purposes)