Immunohistochemical studies discovered that salivary gland lesions strongly expressed four molecules associated with sialadenitis: SSA and SSB (Sjögren’s syndrome autoantigen) and gp91phox (promoter of reactive oxygen species production), single-stranded DNA (marker of apoptotic cells), indicating accelerated apoptosis of salivary gland cells triggered by oxidative stress. The gene discussed is CYBB; the disease is Down syndrome.