???MSI-H???, as used herein, is a term used to classify tumors as having a high frequency of MSI. When five microsatellite loci are analyzed, such as the five microsatellite loci of selected by a workshop on HNPCC at the National Cancer Institute in 1998 for use in the detection of HNPCC, a tumor is classified as MSI-H when at least two of the loci show instability (Boland, 1998 Cancer Research 58