IL6 and breast cancer: Our contrary results may be due to a number of factors which include the following: 1) the IL-6 concentration in breast cancer cells remains below the threshold required for inducing VEGF expression; 2) the time frame for IL-6-induced VEGF expression exceeds the time period we used in the study; and, 3) cell specific induction factors may exist in breast cancer cell that are not present in other cancers.