We found that the transmembrane chemokine CXCL16 (Matloubian et al, 2000; Shimaoka et al, 2000; Wilbanks et al, 2001; Shimaoka et al, 2003) was also frequently methylated in RCC cell lines and in primary tumours but not in normal kidney from non-cancer controls. Here, CXCL16 is linked to renal cell carcinoma.