IFNB1 and neoplasm: Remarkably, only vaccination with p19Arf/IFNβ + Dox MCA cells reduced progression of challenge tumors, whereas cells treated with just p19Arf/IFNβ or Dox displayed little protective effect when compared to mice that received AdRGD-PG-eGFP transduced cells killed by freeze and thaw, a control expected to induce accidental necrosis and tumor antigen release (Fig. 4b).