Altered gene expression patterns as a consequence of EBV-induced epigenetic alterations. (A) Principle component analysis (PCA) of gene expression using a subset of 5,500 genes of uninfected (UN) cells, a vector control (vector), an EBV-positive clone (Pos), and three EBV-negative transiently infected clones (Neg cl1, -cl3, and -cl4). (B) Dendrogram based on PCA showing clustering of samples according to EBV exposure.