PLCB3 and myeloproliferative disorder: In addition to PLCβ1, also PLCβ3 plays a crucial role in haematopoiesis, since PLCβ3-deficient mice develop myeloproliferative disease, lymphoma, and other tumors (44): these mutant mice have increased numbers of hematopoietic stem cells with increased proliferative, survival and myeloid-differentiative abilities.