Radiation is known to arrest cell proliferation and induce apoptosis in cancer cells; however in a study using malignant mesothelioma cell line exposed to radiation, it was observed that there was no change in p27Kip1 levels thus making SphK1 mediated signaling pathway in mesothelioma cells unique [55]. This evidence concerns the gene CDKN1B and malignant mesothelioma.