FFAR2 signaling is necessary for SCFA-driven expansion of colonic Foxp3^+ regulatory T cells and protection from T-cell-transfer colitis, while SCFAs additionally act via HDAC inhibition and mTOR–S6K modulation to stabilize Foxp3 expression and limit pro-inflammatory Th17 responses (Figure 2) (60). This evidence concerns the gene FOXP3 and colitis.