The inhibition of ACVR1C/SMAD2 pathway using a selective inhibitor of ALK4/5/7 receptors, or down-regulation of ACVR1C or SMAD2 by shRNAs, suppressed retinoblastoma cells lines derived from primary tumors or vitreous [251,252]. The gene discussed is ACVR1C; the disease is retinoblastoma.