To characterize Tfh cells, we examined the simultaneous expression of CD3, CD4, CD45RO, CXCR5, ICOS and PD-1 by CD4+ T cells among total PMBC (PD-1+ICOS+CXCR5+CD45RO+CD4+CD3+ cells), and, consistent with the data described above, we observed a significant higher frequency of circulating Tfh cells during acute malaria compared to the same patients AT (Fig 2A) and to HD (S3 Table). This evidence concerns the gene CD4 and Huntington disease.