“…The use of blood-based ctDNA assays to characterize alterations in KRAS , BRAF , EGFR , HER2 , and gene fusions as resistance mechanisms to anti-epidermal growth factor receptor (EGFR) therapy and prognosticate in mCRC, particularly in colorectal liver metastases, has been well-described [ 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 ]. More recent ctDNA assays have been investigated in mCRC with evidence to suggest varied potential clinical applications in this space.…”