F2RL1 and renal cell carcinoma: The expression of PAR2 in five human RCC cell lines, ACHN, Caki-1, 786-O, A-498, SN12K1 and for comparison, primary human kidney tubular epithelial cells (HTEC), was measured by three different techniques; confocal microscopy, qPCR and a Ca2+ ratiometric assay using the fura-2 probe (Fig 2).