Quantitative real-time PCR (qRT-PCR) was used to measure k-ras, h-ras, and n-ras transcript abundance in the Chol-let-7a-treated HCC cells, and these 3 ras genes were found to be reduced by Chol-let-7a treatment (see Additional file 1C). The gene discussed is NRAS; the disease is hepatocellular carcinoma.