In addition, we have demonstrated that JCPyV-infected choroid plexus cells secrete chemokines, including chemokine ligand 2 (CCL2) (67, 68), that are known to disrupt the endothelial integrity of the blood-brain barrier (67, 68), so it is possible that JCPyV accesses brain pericytes following an initial infection of the epithelial cells of the choroid plexus. The gene discussed is CCL2; the disease is infection.