PRDM1 and neoplasm: However, Prdm1fl/flFoxp3YFP-Cre mice remained to develop much smaller tumors with a slower growth rate than WT mice, while a partial deletion of Blimp1 in heterozygous Prdm1fl/+Foxp3YFP-Cre mice also prevented the tumor growth (Fig. 2c,d).