This study demonstrated the benefit of using NOIR-SS and the CV78 filter for the detection of somatic mutations specific to ctDNA. However, the sensitivity of the assay does not suffice for early detection. We extracted plasma DNA from 1 mL whole blood samples for each sequencing reaction; therefore, the sample volume could be increased. Increasing the yield of plasma DNA may be especially beneficial for NOIR-SS, as the sensitivity of detection increases as the number of sequenced molecules increases. As pointed out previously , the low levels of ctDNA prevent early diagnosis of cancer. We should continue to improve our assay technique to overcome this limitation and to detect all molecules present in plasma.