Figure 5. A postulated model mechanism of PML tumor protection in p53^+/R172H mice. PML presence promotes wt p53 activity in response to stress provocation and preserves genomic integrity. In the absence of PML, wt p53 function is compromised through the loss of its co-activator and mutant p53 is accumulated and drives tumorigenesis. Dashed line indicates pathways dependent on PML presence. Grey pathways indicate pathways that are anticipated to be less active when PML is absent.