Drug efficiency and adjusted drug efficiency of primary mesothelioma cells. Nine malignant cell isolates arranged according to their proportion of malignant cells. R = Resistant, drug efficiency less than 40%. An increasing red color represents increased drug efficiency (40-60%, 60-80% and 80-100%, respectively). Adjusting the drug efficiency to the proportion of malignant cells and drug effect on benign cells; seem to increase the sensitivity of cell isolates and effects of several drugs.