In renal cell carcinoma, down-regulation of CXXC4 by siRNA resulted in the up-regulation of some cellular proliferation related genes (FGF18, EGR1, and MYCN), the down-regulation of apoptosis inhibitor proteins BIRC7 and XAF1, and some other important tumor progression factors [14]. The gene discussed is FGF18; the disease is renal cell carcinoma.