Figure 5. Identification of signature proteins expressed by plasma or serum-derived exosomes for classifying five common cancer types and evaluation of random forest classifier.

(A) PCA plot of plasma or serum-derived exosomes from five cancer types. (B) AUROC score of the random forest classifier by including various number of protein features. (C–D) Classification error matrix of a 60% training set and 40% testing set to classify the five cancer types using a random forest classifier for the five selected proteins. The number of samples is indicated in each box. (E) Protein abundance of five selected protein features in 158 samples across five cancer types. Significance was determined by the Kruskal-Wallis test. ****p < 0.0001.