CD70 and neoplasm: CD70 has been reported to be highly expressed in renal cell (clear and papillary types) (Law et al, 2006), thymic (Hishima et al, 2000), nasopharyngeal (Agathanggelou et al, 1995), and brain (astrocytoma, glioblastoma) tumours (Wischhusen et al, 2002).