Treatment with FC-131 and/or PS inhibits CXCR4 signaling through AKT. OCI-AML3 cells were treated with 1 μM FC-131 and/or PS for 24 hours. Then, cells were harvested and immunoblot analyses were performed for CXCR4, GRK3, pAKT, AKT, pERK1/2, ERK1/2, and hsp70. The expression of β-actin in the lysates served as the loading control. Alternatively, activated AKT was immunoprecipitated from the total cell lysates of untreated and treated cells and used for AKT kinase activity assays. Immunoblot analyses were performed for phosphorylation of a GSK3β substrate as well as for pAKT and total AKT in the immunoprecipitates.