Principle component analysis (PCA) and hierarchical clustering analysis of SAM-identified genes. A) PCA of SAM identified genes that discriminate TGCT cells from HCT116 cells (n = 1794); 1180 up-regulated in TGCT cells and 614 genes up-regulated in HCT116 cells. Blue dots represent the 1180 up-regulated genes in TGCT cells and the green dots represent the 614 up-regulated in HCT116 cells, and vice versa. The complete list from SAM analysis is submitted as Additional file 1. B) Hierarchical clustering analysis of the top 50 over- and under-expressed genes from the SAM identified gene list. Genes are color coded based on the group they belong to.