Using anti-ICOS-L antibodies to deplete Tfh in both ApoE−/− 8 and Ldlr−/− 9 mice did not impact atherosclerosis, but using the same strategy to reduce Tfh in mouse models with exacerbated Tfh/pre-Tfh cells was associated with decreased atherosclerosis. This evidence concerns the gene LDLR and atherosclerosis.