SPHK2 has basal activity towards sphingosine; however, SPHK2 can be activated by a variety of factors and conditions, including epidermal growth factor (EGF) in cancer cells Pyne and Pyne (2020) and hypoxia in cerebral microvascular endothelial cells (Wacker et al., 2009). The gene discussed is EGF; the disease is cancer.