Moreover, the neutralization of 4-1BBL and OX-40L on the surface of cells with specific antibodies in Ppm1dLysM-cre mice attenuated the tumor-suppressive effect of Ppm1d deletion in myeloid cells and significantly accelerated the tumor growth to the same ratio as in wild-type mice (Fig. 5h). This evidence concerns the gene PPM1D and neoplasm.