While there is extensive literature on the association of adipose tissue with the invasiveness and the dissemination of breast cancer cells by leptin, hepatocyte growth factor (HGF), collagen VI, interleukin-6 (IL-6) and C-C motif chemokine 5 (CCL5) secreted from adipocytes as well preadipocytes isolated from abdominal and breast adipose tissue [7–13], little is known about the DCIS progression to invasive breast cancer by cross-talk with preadipocytes. Here, IL6 is linked to invasive breast carcinoma.