Alam et al. [53] reported the detection of serum antibodies against AQP5 and AQP1 in patients with SS, and since AQP1 is closely related to AQP5 in the phylogenic tree of human AQPs, the authors also sought to investigate the possible presence of anti-AQP1 autoantibodies in the sera of SS patients [54]. Here, AQP1 is linked to synovial sarcoma.