As for the cancer itself, in the presence of a suggestive clinical and radiological picture, even if the biopsy is non-contributory or doubtful, the presence of the KRAS mutation (and other target genes) will be highly suggestive of adenocarcinoma (the diagnostic values of the biopsy have been greatly improved, especially at the expense of the negative predictive value). The gene discussed is KRAS; the disease is cancer.