CD4 and aneurysm: Several subtypes of CD4+ T cells exist, with the most abundant being regulatory T (Treg) cells, T helper 1 (Th1), and Th2, Th17, which modulate adaptive immune responses by regulating the functions and recruitment of various T helper subsets.[14] Our study found that in ruptured aneurysms, T cells CD4 naive was significantly increased, and a significant correlation between Tregs, plasma cells and T cells CD4 memory resting was observed.