Common examples of acquired resistance to targeted therapy that can be detected by LP include the emergence of KRAS or NRAS proto-oncogene, GTPase (NRAS) mutations under anti-EGFR therapy in CRC patients [40,41] or the detection of the EGFR NP_005219.2:p.T790M mutation after exposure to first- or second-generation tyrosine kinase inhibitors (TKI) [42]. This evidence concerns the gene NRAS and colorectal carcinoma.