Fifteen of the 35 malignant mesotheliomas showed moderate or strong MnSOD expression without and 23 with microwave pretreatment, the corresponding figures for metastatic adenocarcinoma of the pleura being 1 and 2 out of 21 (P = 0.002 and P< 0.001, respectively by Fisher's exact test). Here, SOD2 is linked to malignant mesothelioma.