Previous studies have utilized multiple mouse models with regulatory sequences to direct the expression of PML-RARα under promoters of specific stages (CTSG and MRP8), contributing to antecedent myeloproliferative diseases (MPD) after a long latent period with high WBC counts and different penetrance [14, 15, 18, 20, 27]. Here, CTSG is linked to myeloproliferative disorder.