We found that several genes that display microsatellite mononucleotide runs and frameshift mutations in human MSI positive CRC tumors (e.g. TGFBR2, TAF1B, ASTE1 and others) display equivalent mononucleotide runs in the macaques, but not in the orthologous genes in mice. The gene discussed is ASTE1; the disease is colorectal carcinoma.