IL23A and neoplasm: Mice exclusively deficient for IL-23p19 in their hematopoietic system reproduced the phenotype of IL-23p19−/− complete knock-out mice, including the observation that after CpG, the hematopoietic ablation of IL-23p19 strongly attenuated tumor induction, supporting the paradigm mentioned above that the hematopoietic origin of IL-23 is the decisive enhancer of tumor growth (Figure 5).