IFIT3 and viral infectious disease: We describe: “Classical SGCs” expressing classical SGC markers including FABP7, KIR4.1, GS and CX43, representing 90%–95% of all perisomatic SGC sheaths; OCT6+ SGCs ensheathing the initial axon segments and occasionally involved in mosaic perisomatic SGC sheaths; SCN7A+ SGCs with low/no classical SGC marker expression, forming distinct sheaths specifically around NP neuron subsets implicating a role in pruritus; and an Ifit3+ SGC subset expressing interferon response genes, with implications in protection against viral infection.