CD70 and renal cell carcinoma: The A498, 786-0, and ACHN RCC cell lines and the immortalised HEK293 ‘normal’ kidney cell line were included for FACS analysis, and, as CD70 expression was first described in activated B and T cells, a panel of cell lines with this derivation was also included in the analysis as were the CD19+ and CD3+ subsets of PBMCs.