Furthermore, the capacity of CX3CR1+ CD4 T cells to kill target cells varies according to HLA restrictions with the protective allele DRB1*04:01-restricted cells showing higher cytotoxic activities than their susceptible allele DRB1*08:02-restricted counterparts, which again indicates that cytotoxic CD4 T cell responses correlate with protection from severe dengue disease. This evidence concerns the gene CD4 and dengue disease.