In summary, the observation that HSP90 expression level is a prognostic factor for NSCLC patient survival (independent of EGFR mutational status), coupled with the extreme sensitivity of EGFR wild type NSCLC cells to the Hsp90 inhibitor 17-AAG, suggests that Hsp90 inhibitors may have greater clinical utility in NSCLC than has been previously considered and warrants further investigation of the dependence of other proto-oncogenes on this chaperone protein in NSCLC. This evidence concerns the gene HSP90AA1 and non-small cell lung carcinoma.