JUN and neoplasm: We observed significantly (p = 4.0e-04) less macrophages infiltrating the epithelium in prostates with additional deficiency of Jun. In conclusion, PtenPEΔ/Δ displayed a highly immune infiltrated phenotype, which was substantially reverted in prostates with additional deficiency of Jun. This observation suggests that JUN may be essential for tumor cell recognition by innate and consequently adaptive immune cells.