The results of ACOSOG Z4031 may provide landmark information for the use of proteomic profiling to diagnose lung cancer noninvasively and to provide more accurate predictions of survival. Although the technological developments allowing generalized use of proteomic and genomic analyses are relatively recent, major progress in understanding the molecular basis of lung cancer has been made. Predicting survival is only the first step in the use of proteomics. If a reliable protein profile can be identified that is associated with poor prognosis, these proteins can then be identified and become therapeutic targets. It is not difficult to envision a day when a simple blood test will diagnose a lung cancer, perhaps even before it is clinically apparent, and, at the same time, identify the chemotherapeutic agents to which the tumor is sensitive, allowing individually directed treatment.