CD4 and non-small cell lung carcinoma: To measure pre-existing antitumor CD4+ Th1 response in NSCLC patients, we quantified telomerase-reactive CD4+ T-cell response by IFN-γ ELISpot assay using a mixture of highly promiscuous HLA class II-restricted peptides derived from telomerase as previously described22–25 (Fig. 1a).