The mean number of cells analyzed for nucleolin expression in the central part of the tumor in pulmonary adenocarcinoma was 6176 ± 1045, in pleural infiltration of pulmonary adenocarcinoma was 6186 ± 1470 and in malignant mesothelioma was 7832 ± 2645 (mean ± SD), while for nucleophosmin expression the number of cells analyzed was 6252 ± 1162, 5574 ± 1005 and 8573 ± 1303, respectively. The gene discussed is NPM1; the disease is malignant mesothelioma.