DSG3 and acquired polycythemia vera: In conclusion, EC1 was found to be the most frequently targeted by autoantibodies in PV patients; autoantibodies against entire extracellular Dsg3 (EC1-5), EC1, EC2-3, EC2-5, and EC3-4 were associated with disease severity, and autoantibodies against EC1, EC3-5, and EC2-5 were associated with disease phase.