Classification and Regression tree for differentiating nevi from melanoma using Braf, nuclear p300 and cytoplasmic p300 expression. Nevi samples include both normal and dysplastic nevi cases. Melanoma samples include both primary and metastatic melanoma cases. ‘n’ indicates the number of samples and ‘%’ indicates the percentage of samples available at the respective node. Improvement is an indicator of separation achieved by the application of the respective marker to classify the parent node.