Light micrograph of BAP1 protein loss in a kidney tumour, as detected by an immunohistochemical stain. The tumour cells are the clusters of light blue stained circles. Normal BAP1 positive non-tumour cells (short oval or spindle shaped structures) are present in between the blue clusters of tumour cells. Since the tumour cells lack brown staining, a pathologist can tell that they do not contain the BAP1 protein. BAP1 loss is associated with more aggressive kidney cancer. Magnification: x200 when printed at 10cm wide.