CDKN2B and kidney cancer: We used quantitative RT‐PCR to measure the levels of three TGF‐beta pathway components (TGFB2, INHBA, and SMAD3) and two TGF‐beta targets (THBS1 and CDKN2B) which were previously found to be significantly lower in FLCN‐deficient kidney cancer cells and tumors (Hong et al. 2010).