Fig. 1

Principal component analysis (PCA) showing the clustering of mRNA, long non-coding RNA (lncRNA), and microRNA (miRNA) expression matrices in different samples and different datasets. a–c PCA of mRNA expression between the nasopharyngeal carcinoma (NPC) cluster and normal tissue cluster in the FJCH (a), GSE12452 (b), and GSE13597 (c) datasets. The purple dots represent the NPC samples, and the blue dots represent the normal tissue (control) samples. d–f PCA of lncRNA expression between the NPC cluster and normal cluster in the FJCH (d), GSE95166 (e), and GSE126683 (f) datasets. The blue dots represent the NPC samples, and the red dots represent the normal tissue (control) samples. g, h PCA of miRNA expression between the NPC cluster and normal cluster in the GSE70970 (g) and GSE43039 (h) datasets. The green dots represent the NPC samples, and the blue dots represent the normal tissue (control) samples