Chemosensitivity of mesothelioma cells. Eighteen malignant cell isolates arranged according to their proportion of malignant cells, four benign cell isolates and five cell lines with a pure malignant cell populations to the right. Benign samples in middle on grey background. R = Resistant, more than 50% of cells alive in highest drug concentration. Red color marks a sample where less than 50% of cells were alive. An increasing red color represents sensitivity to an increased drug dilution (1:1, 1:5, 1:25 and 1:125).