Fig. 2From: Differential expression analysis of human endogenous retroviruses based on ENCODE RNA-seq dataPrincipal component analysis of normalized expression values of housekeeping genes in 25 ENCODE RNA-Seq data sets. The first and the second principal components account for 30.67Â % and 21.33Â % of variance, respectively. Circles: normal cell lines; Squares; cancer data sets; Filled symbols: CSHL; Empty symbols: Caltech; crosses in the symbols: single-end sequencingBack to article page