In turn, those genes which were found to be differentially altered in the GEP-A and GEP-B tumor subgroups, included, among other, the KRAS oncogene, the CEACAM1 and CEACAM5 epithelial marker carcinoembrionary antigens, the SERPINB5 gene, as well as the miR-21, miR-221 and miR-222 miRNAs which were all overexpressed in GEP-A vs. GEP-B tumors (Supplementary Tables 2 and 3). The gene discussed is CEACAM5; the disease is neoplasm.