Germline loss of BCL-2 leads to polycystic kidney disease, lymphopaenia, grey fur (due to premature death of melanocytes), growth retardation and early mortality.24, 30, 31 Even with the complex co-morbidities of this model, our results show that young Bcl2−/− and control mice exhibited similar megakaryocyte and platelet counts, indicating that loss of BCL-2 in progenitor cells does not significantly affect the megakaryocytic lineage at steady state in young animals. This evidence concerns the gene BCL2 and polycystic kidney disease.