VTCN1 and renal carcinoma: To test the expression and subcellular localization of B7-H4 ectopic overexpression in renal cancer cells, ectopic overexpression of B7-H4 with and without Flag epitope was carried out in HEK293 cells, transfected with pcDNA3.1 vector containing B7-H4 or B7-H4-Flag.