Though increased CSF CD4:CD8 T-cell ratios have been noted in several conditions, including neurosarcoidosis [42] and myasthenia gravis [43], the causes of a raised CSF CD8:CD4 T cell ratio have rarely been described outside of HIV CSF viral escape and neuro-IRIS, with the latter of these particularly seen during ART initiation [42]. This evidence concerns the gene CD8A and neurosarcoidosis.