CD70 and central nervous system cancer: Subsequent studies have described overexpression of CD70 protein in mantle cell lymphoma samples (Zhu et al, 2002); on chronic lymphocytic leukaemia B cells (Lens et al, 1995; Ranheim et al, 1995); and in the tumour cells of thymic carcinomas (Hishima et al, 2000), undifferentiated nasopharyngeal carcinomas (Agathanggelou et al, 1995), gliomas and meningiomas (Held-Feindt and Mentlein, 2002).