Head and neck reconstructive surgery has continued to evolve at an amazing pace since the introduction of microvascular free tissue transfer. Unfortunately, the postoperative complication remains a timeworn adversary to a successful surgery. Jose P. Zevallos, MD, and colleagues investigate the relationship of oxidative stress created by microvascular tissue transfer and the protective free radical scavenging capabilities of glutathione-S-transferase (GST). In a population of 107 patients, the authors identified the allelic variants of GST, which vary from normal to absent enzymatic function, and discovered that individuals with impaired oxidative recovery were at a significantly higher risk for postoperative complications. Details of the clinical findings, and the implications of preoperative genome analysis, are openly presented.