A clinical vaccination study which assessed the immunogenicity and anti-tumor activity of a vaccine cocktail comprising 4 b3a2-petides restricted to HLA I and one b3a2-petide restricted to HLA II in b3a2-espressing CML patients with stable measurable residual disease, demonstrated immunological activity of the vaccine as illustrated by CML-peptide specific CD4+ T cells in vitro in 13 of 14 evaluable patients (68). Here, CD4 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.