CXCL12 and acute lymphoblastic leukemia: In addition, based on the idea that cold impedes the internalization of membrane receptors54, we stimulated B-ALL cells with SDF-1α or Dex and immediately transferred them on ice (at 4 °C, T = 0) or incubated at 37 °C for 1 or 2 h (T = 1, 2 h).