A few examples include, mice deficient in SphK1 were rendered lymphopenic by FTY720 [115], endogenous SphK1 demonstrated a protective role in renal ischemia whereas SphK2 had a detrimental role [119], and in separate studies SphK1−/− mice demonstrated a very poor survival following cardiac arrest [120]. The gene discussed is SPHK1; the disease is cardiac arrest.