The cause of SS is a multifactorial process that involves interaction between genetic (e.g., HLA, Ro52, IL-10, and TNFα) and environmental (e.g., EBV virus infection [105,106,107,108,109,110], comorbid with rheumatoid arthritis (RA), and radiotherapies) factors [14,111,112,113,114,115,116,117,118,207], which lead to aberrant inflammatory responses mediated by lymphocytes (e.g., T and B cells) and Th17 cells (e.g., IL-17) [76,77,81,82,83,84,85]. This evidence concerns the gene IL17A and rheumatoid arthritis.