John Trombley, a biomedical lab technician at the U.S. Air Force School of Aerospace Medicine, works on exome sequencing to observe gene expression under hypoxic conditions for Air Force personnel. Gene expression can dramatically change to cope with environmental stressors. Efforts are underway to determine what genes are either up or down regulated under hypoxic conditions experienced by flight personnel. (U.S. Air Force photo/Richard Eldridge)