KRAS and colorectal carcinoma: Recently, Balschun et al analyzed the genotypes of the KRAS, neuroblastoma RAS viral (v-ras) oncogene homolog, phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit α (PIK3CA) exon 20 and BRAF genes in synchronous and metachronous primary CRCs and reported a certain grade of heterogeneity in synchronous CRC (SCRC) patients (65%).