Over the past 10 years, liquid biopsy has attracted substantial attention as a supplement or alternative biomarker to conventional biomarkers (AFP, AFP-L3, and PIVKA-II) and tissue biopsy for tumor diagnosis and monitoring (Chen & Zhao, 2019; Crowley et al., 2013; Kondo, Kimura & Shimosegawa, 2015). Here, AFP is linked to neoplasm.