Figure 2

Diagram of the classification tree for patients with HCC and healthy controls. The squares are the primary nodes and the circles indicate terminal nodes. The mass value in the root nodes is followed by the intensity value. For example, the question forming the first splitting rule is: Are the intensity levels of the peak at 4177.02 m/z lower or equal to 5.256? Samples that follow the rule go to the left "yes" terminal node, and samples that do not follow the rule go to a "no" daughter node to the right. The number of control or HCC samples in each node are shown.