Notably, we detected considerably higher RNase1 plasma levels in HCC patients than in normal individuals (~0.4 μg/ml)23,30 (Fig. 1g) and a strong positive correlation of RNase1 expression in HCC patients’ tumor sections with that in paired plasma samples (R = 0.60; Fig. 1h), suggesting that tumor cells are major sources of increased RNase1 expression in HCC patients. Here, RNASE1 is linked to hepatocellular carcinoma.