To tackle the follicular nature of CD4+ T cells in the lymphoid aggregates, we performed IF stainings of CD4, CXCR5 together with NFATc1, again after having established detection on tonsils, follicular lymphoma of the spinal cord, and PCNSL of the brain (Supplementary Figures 3P–R). This evidence concerns the gene CXCR5 and follicular lymphoma.