AFP and hepatocellular carcinoma: The SELEX process showed that an increasing number of oligonucleotides led to an apparent aptamer-enrichment for LCN2, while the aptamer binding signal was not observed in either the non-specific targets (GST, BSA and HSA) or potential HCC biomarkers (AFP) during the selection processes (Fig. 3, Supporting InformationFigures S1 and S4).