Liquid biopsy can be used for early diagnosis (screening), recurrence of cancer (monitoring), and anticancer drug effect (companion diagnostics) using Circulating Tumor Cell* (CTC), a cfDNA derived from cancer cells. The cancer cell-derived cfDNA is analyzed through NGS technology and bioinformatics to see if there is a mutation that causes cancer, and whether it can be effective against the anticancer drug. It is a state-of-the-art personalized precision medical service that confirms whether there are cancer cells.*Circulating Tumor Cell (CTC): Cancer cells circulating in blood vessels