Since Caki-1 cells contributed to up-regulation of ICAM-1, VCAM-1, E-selectin and CD44 V3 and V7 in unstimulated HUVEC, but down-regulation of ICAM-1, VCAM-1 and E-selectin in TNF-alpha stimulated HUVEC and further increased CD44 V3 and V7, conditioning of the endothelium by RCC could depend on the presence of TNF-alpha. Here, CD44 is linked to renal cell carcinoma.