Another study found that mTOR wasalso a profibrotic signal involved in the excessive inflammatory response andfibrotic remodeling of AF through the C-X-C chemokine ligand 12/C-X-C chemokine receptor type 4 (CXCL12/CXCR4) axis [103]. The gene discussed is CXCR4; the disease is atrial fibrillation.