VHL and renal cell carcinoma: When compared with the patients with sporadic RCC plus those with VHL–RCC (total N=10), the patients with VHL but no RCC (N=13) had fewer CEPs, with a median (range) of 0.15 cells μl−1 (0.07–0.55) vs 0.97 cells μl−1 (0.39–5.88) (P<0.01) and also fewer mCECs, with 0.26 cells μl−1 (0.11–2.11) vs 0.93 cells μl−1 (0.19–11.75) (P=0.02) (Figures 4A and B).