SPHK2 and malignant colon neoplasm: The effects of NaBT in colon cancer cells are mediated by SphK2 which acts as a negative regulator of NaBT-induced apoptosis, as evidenced by the study showing that down-regulation of SphK2 by siRNA potentiates NaBT-induced apoptosis in HCT116 colon cancer cells, whereas its overexpression diminishes apoptosis rate [105].