Photomicrographs demonstrating typical patterns of HGF and Met expression by immunohistochemistry in distinct nephrogenic rests and Wilms tumours from different patient samples. First row, a perilobar nephrogenic rest (PLNR) with strong, diffuse HGF staining in blastemal cells. Second row, a Wilms tumour demonstrating no immunoreactivity. Third row, an intralobar nephrogenic rest (ILNR) with strong Met expression in the stromal compartment. Fourth row, a Wilms tumour with strong stromal immunoreactivity. Low power, original magnification ×200; high power, original magnification ×400.