The inverse correlation between TFPI-2 and CD133. From left to right, expression of TFPI-2 compared with that of CD133 (n = 218) as low to low (1, n = 40), low to high (2, n = 74), high to low (3, n = 63) and high to high (4, n = 41) (r = -0.3876, P = 0.0001).