We treated 129S1/SvImJ background Col4a3−/− Alport syndrome mice, which have a shorter lifespan than C57BL/6 background Col4a5 G5X Alport syndrome mice, with losartan or metformin alone, or in combination, via drinking water from 4 weeks old (Supplementary Fig. S9b). Here, COL4A5 is linked to Alport syndrome.