- Reproducibility and expression of skin biomarkers in sun-damaged skin and actinic keratoses. Einspahr, J.G., Xu, M.J., Warneke, J., Saboda, K., Ranger-Moore, J., Bozzo, P., Duckett, L., Goldman, R., Lin, P., Buckmeier, J., Alberts, D.S. Cancer Epidemiol. Biomarkers Prev. (2006)