Moreover, in this proof-of-concept prospective study of liquid biopsy monitoring, we demonstrated that continued circulating RAS wild-type ctDNA status is a valuable biomarker for prolonged tumour response to anti-EGFR therapy, and that RAS mutation emergence events were used to predict resistance to anti-EGFR therapy and an imminent radiological progression in patients with mCRC. Here, EGFR is linked to neoplasm.