IL6 and breast cancer: IL-6 has been shown to increase T47D and MDA-MB-231, but not MCF-7, transmigration when used as a chemoattractant in Boyden Chamber-based assays (IL-6 concentrations used ranged between 10 and 200 ng/mL) [34]; however, the direct stimulation of BC cell lines with IL-6 did not alter the migratory ability of MDA-MB-231 and MCF-7 cells in the current study.