Incubation of whole-blood samples in plastic tubes in the presence of culture medium without LPS induced a slight activation and maturation of DCs, which emphasised differences between patients and controls, resulting in significantly higher percentages of CD80+ DCs (9.80 ± 1.72 vs 3.86 ± 0.77%, P=0.004) and CD83+ DCs (14.86 ± 3.51 vs 4.53 ± 1.42%, P=0.011), and higher DC expression of CD86 (163.14 ± 20.33 vs 86.47 ± 10.11%, P=0.028) in breast cancer patients than in control subjects. This evidence concerns the gene CD80 and breast cancer.