DCIS.com proliferation (1.75 ± 0.09, P < 0.0001) promoted by co-culture reverted to a single culture state in the presence of 3 μg/ml IL-6 NAb or IL-6R NAb (1.21 ± 0.10, P = 0.0037 or 1.06 ± 0.07, P = 0.0002), and migration (1.52 ± 0.04, P < 0.0001) enhanced by co-culture was also significantly decreased in IL-6 NAb- or IL-6R NAb-treated DCIS.com (1.11 ± 0.02, P < 0.0001 or 1.18 ± 0.09, P = 0.011) (Fig. 4c). This evidence concerns the gene IL6 and ductal breast carcinoma in situ.