IL-17 signaling-related cytokine levels are greater in supernatants from BMSCs co-cultured with leukemia cells. Supernatants from the cultures were harvested after 48 hours and tested for soluble factors using an immunoblotting assay. The supernatants were from BMSC mono-cultures (black bars), TF1, TF-1α and K562 leukemia cell mono-cultures (white bars), CD34+ cells mono-cultures (grey bars), BMSCs co-cultured in transwells with leukemia cells (black and white stripped bars) and BMSCs co-cultured with CD34+ cells (black and grey stripped bars). The relative expression of selected cytokines was measured using array protein panel A (R&D System). The relative concentrations of IFN-γ, CD40L, CCL2 and IL-8 were calculated as a mean pixel density after normalization with positive control and background subtraction. The sample labeling legend is at the top right. The histograms represent results of 3 experiments with BMSCs from three different healthy donors.