Similarly, negative hyper-selection for mutations in the KRAS, NRAS, PTEN, and EGFR extracellular domain; amplifications of HER2 and MET; and fusions in ALK, RET, and NTRK1 captured by circulating tumor DNA (ctDNA) helped identify colorectal cancer patients with increased benefit from the anti-EGFR antibody panitumumab in the phase III PARADIGM study [48]. This evidence concerns the gene RET and colorectal cancer.