PECAM1 and cyst: Across n=3 Pkd1RC/RC mice and 40 individual SPP1+ CD31+ vessels, we found 60% (24 out of 40) of the SPP1+ vessels to be within 100 μm from the nearest cyst boundary, whereas the remaining 40% (16 out of 40) were greater than 100 μm away from cysts.