IL17A and dry eye syndrome: IL-17A may be related to inflammation in dacryoadenitis (Jie et al., 2010; Tan et al., 2014) and in the salivary glands (Fei et al., 2014), while MMP-9 may be involved in the early phase of dry-eye syndrome and tissue fibrosis (Sambursky et al., 2013; Lopez-Miguel et al., 2016).