One study utilizing LC-MS/MS identified the seven proteins (Ig alpha-1 chain C region, lacritin, lactoferrin, lipocalin-1, lysozyme C, polymeric Ig receptor, and a prolactin-inducible protein) that were noted in tear fluid samples collected from both non-SS dry-eyed individuals and SjD dry-eyed individuals [43]. Here, LTF is linked to synovial sarcoma.