Prostate cancer has been extensively studied and successfully identified using different techniques, such as serum analysis combined with PCA-SVM [228]; detection of prostate specific antigens [229,230,231,232]; EVs combined with CNN [230]; miRNAs [233]; different multivariate techniques, e.g., PCA-LDA and PCA-SVM [234]; and urine profiling [235]. Here, KLK3 is linked to prostate cancer.