However, a previous study showed that the presence of either p53-null or p53-mutant fibroblasts evidently increased the rate of metastatic spread of PC3 tumors when PC3 prostate cancer cells were co-inoculated with WT, Trp53-KO, or Trp53-mutant MEFs into the SCID mice13. This evidence concerns the gene TP53 and prostate cancer.