TWIST1 and acute lymphoblastic leukemia: Cell viability assay using YFP-positive NALM6 cells following TWIST1 or SNAI2 siRNA-mediated knockdown, which sensitized NALM6 cells co-cultured with MSCs to DEX (Figures S5B and S5C), demonstrates that the upregulation of TWIST1 and SNAI2 in Adh ALL cells is implicated in MSC-mediated drug resistance.