MAPK1 and leukemia: Subsequently, we performed Western blotting analysis (Figure 5A), and the assay results revealed that after upregulation of Nrf2 in MSCs and co-culture with leukemia cells, we found that the expression levels of PI3K/AKT and ERK pathways downstream of the SDF-1/CXCR4 axis, which are significantly associated with migration and invasion, tended to increase in leukemia cells.