SOAT1 and Immunodeficiency: Well-known examples are the Toll/Toll-like receptor (TLR), immune deficiency (IMD)/tumor necrosis factor-α (TNF-α), JAK/STAT and JNK signaling pathways and their respective downstream transcriptional activators, nuclear factor kappa B (NF-κB), STAT and AP-1, which regulate innate immune responses in both Drosophila and mammals [1–4].