SPHK2 and nervous system disorder: Notably, many of these DEGs have been associated previously with neurological disease including SPHK2 (sphingosine kinase 2); P2RX7 (purinergic receptor P2X 7); SMPD4 (sphingomyelin phosphodiesterase 4); ASAH1 (N-acylsphingosine amidohydrolase 1) (Supplementary Tables S5 and 6).