This is consistent with data from human xenografts (Noguera-Troise et al, 2006) and in situ hybridisation data for Dll4 in human bladder cancer (Patel et al, 2006) and human renal cell carcinoma (Mailhos et al, 2001; Patel et al, 2005). Here, DLL4 is linked to hereditary clear cell renal cell carcinoma.