CD4 and Familial prostate cancer: A subset of five flow cytometry features was selected (CD8+CD45RA−CD27−CD28−; CD4+CD45RA−CD27−CD28−; CD4+CD45RA+CD27−CD28−; CD3−CD19+; CD3+CD56+CD8+CD4+) from a set of 20 features, which could potentially discriminate between the presence of benign disease and prostate cancer.