Cancer tumor and benign kidney samples can be separated using hierarchical cluster analysis. The 69 metabolites identified as significantly different (P ≤ 0.05) between cancer tumor and matched benign kidney tissue from six patients were used to generate the cluster based on Euclidean distance. Cancer tumor or benign samples were determined by histopathology evaluation. Metabolites are listed on the y-axis. Each patient is represented by a number (1 to 6) on the x-axis. Cancer tumor (C) and matched benign (B) samples were used for the analysis. Four of six cancer tumor samples were assigned to the same major cluster and five of six benign samples were assigned to the same major cluster.