Table 1. Important acronyms and definitions.

Acronym	Definition
CIMP	CpG Island Methylator Phenotype (high or low). Excessive methylation of the CpG islands in gene promoters which results in transcriptional silencing. A panel of genes is used to determine this status.
MSI-H	Microsatellite Instability High. Errors at repeating nucleotides of 1-6 base pairs in length that may result in frameshift mutations. A panel of microsatellites determined by the National Cancer Institute, colloquially referred to as the Bethesda markers, is used to assess this trait.
MSS	Microsatellite Stable
OIS	Oncogene-induced senescence. A tumor-suppressive mechanism by which oncogene activation triggers a process to initiate cell growth arrest.