CARD11 is a scaffold protein — it acts like a docking station that brings inflammatory signaling molecules together. When a microglial receptor detects a threat, CARD11 assembles the NF-κB inflammatory signaling complex, like a conductor organizing an orchestra.
Why MCHS matters: CARD11 was also dramatically downregulated (log2FoldChange = −5.16 — over 30-fold reduction). This means microglia's inflammatory signaling infrastructure is fundamentally broken — not just overactive, but *dysregulated*. The cells can't coordinate their inflammatory response properly, leading to chaotic, uncontrolled inflammation in the MHS brain.