Unsupervised clustering of 16 PTCL-u and 17 AITL tissue samples. Dendrogram of the 33 lymphoma tissue samples based on PCA of the first 25 components (accumulated variance 95%). CD30: + denotes expression in more than 50% of neoplastic cells; - denotes absence of expression or low level of expression of CD30 in neoplastic cells. The percentage of tumor cells is represented by a gray scale (light gray: 30%-50% tumor cells; medium gray: 50%-70% tumor cells; and dark gray: > 70% tumor cells).