Fig. 1

Study design and principal component analysis showing the relationship among the tissue groups in patients with HCC of different viral etiology. The analysis was based on the results of the normalized expression levels of 68 long non-coding RNAs (lncRNA) detected in tumor tissues and their surrounding non-tumorous tissues using disease-related human LncRNA Profiler. a Study design illustrating the different groups of patients included in the profiling of the expression of disease-related lncRNAs. HCC, hepatocellular carcinoma; HBV, hepatitis B virus; HCV, hepatitis C virus; HDV, hepatitis D virus. b Principal component analysis of tumor (T) and surrounding non-tumor tissue (NT). c Principal component analysis of tumor (T) and surrounding non-tumor tissue (NT) of 6 groups of patients according to the viral etiology. Each principal component contribution rate is shown in each axis. PCA Principal component analysis; PC principal component