The tumours were characterized by diffuse CK7 expression, diffuse CAIX expression in a membranous pattern (8/11 [73%]), diffuse cytoplasmic CD10 expression (8/8 [100%]), diffuse cytoplasmic CAM5.2 expression (11/11 [100%]), and variable cytoplasmic desmin reactivity in the smooth muscle component (10/10 [100%]). The gene discussed is DES; the disease is neoplasm.