AFP and hepatocellular carcinoma: Using the combination of ctDNA and AFP as detective indicators distinguished HCC patients from non-cancer control participants with a SEN of 0.82 (95% CI [0.77–0.86], I2 statistic: 85.81%) and a SPE of 0.84 (95% CI [0.76–0.90], I2 statistic:93.32%) (Fig. 6).