These studies, combined with the fact that LRP1 appears to be encoded by a general hypoxia-regulated gene (Koong et al, 2000; Wykoff et al, 2000; Zatyka et al, 2002), suggest that the microenvironmental conditions surrounding aggressive gliomas and other tumours might stimulate uptake of Angiopep-2 and ANG1005. This evidence concerns the gene LRP1 and central nervous system cancer.