CXCL12 and acute myeloid leukemia: Analogously to activation of the Jak/Stat pathway, application of known activators of the PI3K pathway including FLT3L, SCF and SDF-1α broadly grouped AML samples by the magnitude of their signal transduction responses (Fold metric) and overall pathway activity (Total metric) represented by measurements of p-Akt and p-S6 (Figure 2C).