To test if SIGIRR overexpression was able to dampen intrinsic IL1 signaling in RCC cells, we transiently transfected A498 with SIGIRR expression plasmid or empty vector; as expected, SIGIRR-transfected cells showed very high levels of SIGIRR mRNA and protein (Figures 5A, C). Here, IL1B is linked to renal cell carcinoma.