a: PCA of the whole gene, b: PCA of m6A genes, c: PCA of m6A-related lncRNAs, d: PCA of lncRNAs used for risk scores construction. The results showed that compared with m6A genes, m6A-related lncRNAs, and other genes, the lncRNAs used for risk score construction had the best discrimination between high-risk group and low-risk group samples. This means that the lncRNAs used to construct the risk score can well distinguish samples from the high-risk group and the low-risk group.