To determine the potential impact that reduced cohesion gene expression may have in cancer, we focused our attention on 10 genes with key roles in sister chromatid cohesion, including those that encode; 1) the cohesin complex (SMC1A, SMC3, RAD21, STAG1, STAG2 and STAG3); 2) cohesin loaders (MAU2 and NIPBL); and 3) proteins required for the establishment of cohesion (ESCO1 and ESCO2). This evidence concerns the gene STAG2 and cancer.