Although Kim1 expression was undetectable in control and mutant kidneys at E18.5 (Supplementary Fig. 8C,D), co-immunofluorescence in P7 mutants revealed patches of non-dilated LTL-positive/Kim1-positive cells, often near cysts, but excluded from the cyst lining cells, versus no staining in controls (Fig. 9C,D). Here, HAVCR1 is linked to cyst.