To validate all these observations, we measured by RT-PCR the mRNA levels of protein-coding SIGIRR isoforms (201-202-203-220) in a total of 20 primary ccRCC samples (including the 12 array samples) and 13 normal kidney tissues; we confirmed significantly lower levels of SIGIRR mRNA in ccRCC as compared to the normal epithelium (Figure 1D). The gene discussed is SIGIRR; the disease is nonpapillary renal cell carcinoma.