The present invention is related to peptides that can be used to reduce the immune response against FVIII or to induce tolerance to human FVIII in patients with, e.g., hemophilia A. Furthermore, the peptides can be used for immunodiagnostic purposes to detect FVIII-specific CD4+ T cells to monitor patients with hemophilia A during replacement therapy and during immune tolerance induction therapy.本發明係關於可用於減少針對FVIII之免疫反應或誘導患有例如A型血友病之患者對人類FVIII之耐受性的胜肽。此外,該等胜肽可出於免疫診斷目的用於偵測FVIII特異性CD4+ T細胞,以便在替補療法期間及在免疫耐受誘導療法期間監測患有A型血友病之患者。