2.1. Construction process of the lncRNA risk score model

LncRNA transcriptome expression data of 180 HCC patients were downloaded from the Tanric database (https://www.tanric.org/home). 17 Corresponding clinical information of 180 HCC patients was downloaded from TCGA database (https://xenabrowser.net/datapages/). We omitted lncRNAs expressing value with coefficient of variance >0.1 and selected survival‐related lncRNAs from training samples by performing Cox analysis (P < .05). Then, we used the random survival forests‐variable hunting algorithm to further filter nodes until nine lncRNAs were screened out. 18 We developed risk score models to estimate prognosis risk as follows 16 , 19 : Riskscore=∑i=1N(lncRNAexp∗coefficientCOXi) , where N represents the lncRNAs number in the model, lncRNAexp is the lncRNAs expression value, and coefficientCOXi is the coefficient of lncRNAs in the Cox analysis. We selected signatures which predicted the HCC OS with AUC > 0.7 and log‐rank P < .05 from all 2⁹‐1 = 511 signatures.