IL4R and brain neoplasm: In addition to demonstrating expression of IL-4R on cancer cells including brain tumour cells, we have extensively studied the structure and signal transduction of IL-4R on cancer cells (Kawakami et al, 2000; Leland et al, 2000; Murata et al, 1995, 1997a,b, 1998a,b; Obiri et al, 1993, 1997).