HCAR1 and Arthritis: 1. Reduces inflammation in colitis models via GPR81.2. Inhibits overactivation of inflammasomes through MCTs in colitis.3. In murine arthritis models, the expression of the transporter protein SLC5A12 is upregulated, subsequently leading to an enhancement in the production of interleukin-17 (IL-17) by activating the PKM2/STAT3 signaling cascade.4. Induces immunosuppression in septic acute kidney injury via the PD-1/PD-L1 pathway causing lymphocyte apoptosis.