Since this technology can easily analyze up to 40 SNPs in a single reaction with reasonable sensitivity and specificity and can give relative abundance of each SNP [22], we evaluated the clinical utility of this platform as a non-invasive method for CRC monitoring by analyzing plasma samples from CRC patients whose tumors have known KRAS mutations by using a multigene format MALDI-TOF MS platform. The gene discussed is KRAS; the disease is colorectal carcinoma.