The University of California, Davis' Kiho Cho and his colleagues report in Experimental and Molecular Pathology that structural changes occur in the mouse genome that are age-dependent as well as tissue-specific. Cho and his team examined such changes in conjunction with retroelement transposon activity, and found that liver genomes were larger than ones isolated from other organs and that genome size peaked around five weeks of age. "The data from this study provided evidence that there are multiple variant alleles/isoforms of the genome from an individual in association with age and tissue type," they write. "Thus, a new protocol/system, which addresses the dynamic property and/or multiplicity of the genome, needs to be developed to decode and establish the personal genome."

Researchers from Creighton University School of Medicine in Omaha, Neb., report in Experimental and Molecular Pathology that vitamin D receptor expression may be related to esophageal adenocarcinoma tumor progression and response to therapy. They examined 15 samples from patients being treated for esophageal adenocarcinoma and found that elevated expression of vitamin D receptor correlated with tumor non-response to neoadjuvant therapy and decline with de-differentiation of tumors. However, the researchers note that while "it is plausible that the extent of VDR expression is related to tumor progression and response to therapy, ... it is equally as plausible that these data are merely random."