JCPyV is a neurotropic virus in the absence of an appropriate immune response, such as with the use of immunosuppressive drugs or AIDS, because its replication is dependent on transcriptional factors in glial cells and neurons, including Jun, NF-1, GF-1, Sp1, Sμbp-2, Purα, and YB-1. This evidence concerns the gene IGHMBP2 and AIDS.