Immunohistochemical (IHC) staining of a specimen from the 1st surgery for the left frontal tumor showed a loss of PMS2 expression in tumor cells and normal tissue as vascular endothelial cells and preserved expression of MLH1, MSH2, and MSH6 in both tumor cells and normal tissue (Additional file 2: Figure S1a-d). The gene discussed is MSH2; the disease is neoplasm.