Ischaemia is known to affect gene expression in both normal and malignant tissue, but this effect has not been studied in renal cell carcinoma (RCC). 10 tumour samples were stored at 4, 22, or 37 °C or frozen for 5, 30, 60, 120 and 240 min; thereafter, RNA integrity and gene expression were assessed. Longer ischaemia time and warmer environment significantly altered expression of >4,000 genes. However, RNA was also shown to remain intact for up to 4 h after resection regardless of the conditions. These results could have important implications for tumour profiling, where procurement conditions can vary.