We also investigated absolute cell numbers of CD14++/CD16+ monocytes in PB and CSF of PRES patients and aged-matched controls, which provided similar differences as seen for relative cell numbers (CSF: cells per milliliter, mean (SD); PRES 159.1 (164.7), control 57.7 (79.2), p = 0.02; blood: 1000 cells per milliliter, mean (SD); PRES 70.3 (58.8), control 24.8 (9.9), p < 0.01). The gene discussed is CD14; the disease is Posterior Leukoencephalopathy Syndrome.