Issues

The cover image is a photomicrograph (400X) showing intact nuclear staining for PMS2 expression in malignant colon cells. PMS2 is one of four mismatch repair proteins, including MLH1, MSH2, and MSH6, that are normally stained for immunohistochemically in screening for Lynch syndrome. Cells in this image were stained using the PMS2 antibody clone A16-4 (BD PharMingen) at a dilution of 1:300. The absence of any one of the four stains in a tumor raises suspicion of an underlying Lynch syndrome mutation in that gene. This staining approach is the most cost-effective method for screening all newly diagnosed colorectal cancer patients for Lynch syndrome. See articles by Dinh et al. (beginning on page 9) and Hampel and de la Chapelle (beginning on page 1) for more information.