Targeting tumour-reactive CD4+ T cells in peripheral blood raises questions regarding the choice of tumour-associated antigens.20 Telomerase activity maintains tumour cell immortality by protecting cancer cells from telomere-dependent cell death, and telomerase overexpression is reported in the majority of human cancers.38,39 The critical activities of telomerase during the oncogenesis process may also prevent immune escape via an antigen-loss mechanism.1 Thus, the good prognostic value of a CD4+ T-cell response against telomerase highlights the critical functions of this antigen.40 The gene discussed is CD4; the disease is cancer.