The increase in the proportion of CD4+CXCR5+CCR7lowPD-1high cTFH in CD4-lymphopenic ALPS patients was associated with a reduced absolute number of these cells compared to non-CD4-lymphopenic ALPS patients, reflecting the differences in the total CD4 T cells between these 2 groups. This evidence concerns the gene CXCR5 and autoimmune lymphoproliferative syndrome.