CXCL12 and Thrombocytopenia: As megakaryocyte migration to the sinusoidal niche, mediated by CXCL12 signalling, is a key step in thrombopoiesis, these findings may explain observations of thrombocytopenia as an adverse effect in clinical trials investigating the potential use of Pim kinase inhibitors as cancer treatments [36,37,38,39].