The v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS)-LCS6 (G>T) polymorphism is located in the KRAS2 gene (region 12p12.1, 6 exons; exon 5 has an alternative splicing site and results in the B isoform, KRASB) (9) and appears to reduce the lifespan of head and neck cancer patients. This evidence concerns the gene KRAS and head and neck cancer.