Hierarchical clustering of Merkel cell carcinoma samples. Samples were clustered based upon the expression pattern of 45 differentially expressed genes between tumors of poor and good prognosis patients ( and 1.5-fold cutoff). Individual samples are represented on the -axis with poor prognosis patients in light blue (“poor”), good prognosis in green (“good”), and moderate prognosis in yellow (“mod”). Differentially expressed genes are shown on the -axis. Clustering of (a) good and poor prognosis patients; (b) good, moderate, and poor prognosis patients. The scale of gene expression values are standardized such that genes are shifted to a mean of zero and scaled to a standard deviation of one.
