To test the association of ctDNA-positive status in plasma with residual disease detection after surgery, VAFs of BRAF p.V600E and KRAS p.G12/p.G13 variants were measured in cfDNA from plasma of 18 CRC patients prior to surgery (i.e., baseline sample) and four to 50 days after surgery (Figure 3). The gene discussed is KRAS; the disease is colorectal carcinoma.