The clinical utility of LP has been demonstrated for the detection of epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients or for the detection of KRAS proto-oncogene, GTPase (KRAS) mutations in patients suffering from metastatic colorectal cancer (CRC) [36,38]. This evidence concerns the gene EGFR and metastatic colorectal cancer.