IL27 and acute lymphoblastic leukemia: Furthermore, IFN-γ, TNF-α, and IL-27 expression was elevated in T-ALL cells (GFP+/CD45+) infiltrating the meninges, but not in leukemic cells from the the BM or thymus of T-ALL mice, suggesting a unique inflammatory crosstalk between leukemic cells and the meningeal microenvironment (Figure 8G).