Unsupervised clustering of 7 NKTCLs, 2 NKTCL-derived cell lines, and 16 PTCLs, NOS. Dendrogram of 23 lymphoma tissues and 2 cell lines based on principal component analysis demonstrated 2 major clusters of NKTCL including tumor-derived cell lines and PTCL, NOS, respectively. T1-T7: 7 NKTCL samples, SNK6, SNT8; C1-16: 16 PTCL, NOS samples.