<s>[INST] Please explain the procedure kras mutation and the posibility of the drug erbatax on a rectal tumor with metastices to the liver [/INST] Hi welcome to Healthcaremagic Hi..., Kras is a gene present in the chromosome, any change in the genetic material will lead to mutation and result in the production of the tumor... the Drug will prevent the multiplication and production of the tumor cells.. hence used in the rectal cancer.. Hope I have answered your question.. Takecare... </s>