Recently, a protein has emerged as a potential renotrophic factor: bone morphogenetic protein-7 (BMP-7). In a preventive protocol, BMP-7 treatment was found to significantly decrease renal injury in a rat model of ureteral obstruction (UUO), when treatment was initiated at the time of injury. Subsequent studies suggested that BMP-7 treatment also attenuated renal fibrosis when administered after renal fibrosis had begun. This treatment protocol was also found to increase significantly renal function from the levels measured in the vehicle-treated group. BMP-7 also partially reversed the diabetic nephropathy induced in rats by a single dose of streptozotocin. It restored glomerular filtration rate (GFR), decreased the excretion of protein, and restored histology towards normal. These studies also highlight the value of histological parameters as indicators of renal function and the potential of renal homeostatic factors in the treatment of kidney disease.