ABL1 and cancer: To assess whether decreased MMP9 expression and function by ABL allosteric inhibitors in co-cultures of MSCs with cancer cells is mediated by inactivation of ABL kinase activity specifically in the lung cancer cells, PC9 and HCC827 cells were transduced with lentiviruses encoding scramble control shRNA (SCR) or ABL1+ABL2 shRNAs (AA), and these cells were cultured with or without MSCs followed by FACS sorting for analysis.