Along these lines, recently developed humanized mouse models in which mice are engrafted with human thymus or human glial cells (39, 73) may present opportunities to study the role of JCV tAg-mediated RIG-I inhibition in the maintenance of persistent infection in the kidney, JCV neurotropism, and pathogenesis of PML. This evidence concerns the gene RIGI and progressive multifocal leukoencephalopathy.