Different aspects of HERVs, including their roles in autoimmunity and gene/protein expression, have been emphasized in the context of immune-mediated diseases such as multiple sclerosis (MS) [4], neuromyelitis optica with aquaporin-4 autoantibodies [5], systemic lupus erythematosus (SLE) [6], and Sjögren’s syndrome (SjS) [7]. Here, AQP4 is linked to systemic lupus erythematosus.