ZIOPHARM Oncology, Inc., is a biotechnology company. The Company employs gene expression and control technology to deliver deoxyribonucleic acid (DNA) for the treatment of cancer. The Company's technology employs Intrexon Corporation's RheoSwitch Therapeutic System to turn on and off, and precisely modulate, gene expression at the cancer site in order to improve the therapeutic index. As of October 18, 2013, the technology was being evaluated in Phase II clinical studies of the immune system cytokine interleukin-12 for the treatment of breast cancer and advanced melanoma. The Company is also developing small molecules as potential cancer therapeutics.