Lung tissue paraffin blocks and slides were collected from cases that underwent surgery, biopsy, or cytological examination of the lung tumor (Table 1). Multiple fresh "normal" lung tissue (adjacent and distant from the malignant lesion) and tumor samples, frozen in liquid nitrogen within 20 minutes from excision at surgery, were also collected from 436 cases (about 46% of the surgical cases). All biospecimens and accompanying forms were labeled using 2-D bar codes. Biospecimens were shipped according to international regulations on alternate weeks following different procedures based on biospecimen type, and tracked through a database [18] that stores detailed information on sample descriptions, dates, sample transfers, aliquoting, freezer locations, and material type that is linked to the repository for easy access and exchange of laboratory information.
