SPHK1 and stroke disorder: SphK2, but not SphK1 has been shown to be upregulated by HP and isoflurane in the brain (Wacker et al., 2009; Yung et al., 2012) in a HIF-dependent manner (Wacker et al., 2012) and pharmacological inhibition (Wacker et al., 2009) and genetic deletion of SphK2 (Wacker et al., 2012; Yung et al., 2012) were shown to abrogate the protective effects of preconditioning in experimental stroke.