Down-regulation of RSF-1 bysiRNA increases the efficacy of radiotherapy via stimulation of apoptosis,DNA damage, and cell cycle arrest in cervical cancer cells.85 Apart from RSF-1, glucose transporter-1 (GLUT-1)is also responsible for resistance of cancer cells to radiotherapy;86,87 siRNA-induced GLUT1 inhibition render cancer cells more responsiveto radiotherapy by induce their DNA damage and apoptosis.88 These two studies illustrate that siRNA is apotential strategy in enhancing the efficacy of radiotherapy. The gene discussed is SLC2A1; the disease is cancer.