A slow-cycling YFP+Ki-67– cells were also abundant at the interface of normal tissue and SV40+ prostate cancer cells that metastasized to the liver and bone in TRAMP × ADAM12-tTA-CreYFP mice (Fig. 5i), further suggesting a role for ADAM12+ MSCs in the metastatic niche. This evidence concerns the gene MKI67 and prostate cancer.