The similarity of the lipids that accumulate in nGD (GlcCer/GlcSph), Krabbe (galactosylsphingosine), and NPC (in which small but significant amounts of GlcCer accumulate in addition to the primary storage material, cholesterol) suggest that more complex GSLs such as ganglioside GM2, which accumulate in Sandhoff disease, cannot trigger the IFN response, whereas the more simple GSLs do trigger this response, although to a different extent. The gene discussed is NPC1; the disease is Sandhoff disease.