Multiple clinical trials have demonstrated that the small-molecule Syk inhibitors R406 and fostamatinib (R788, an oral prodrug metabolised to R406 in vivo) have desirable effects on rheumatoid arthritis and allergic rhinitis with few and acceptable side effects (Weinblatt et al., 2010; Kang et al., 2019; Wu et al., 2019). This evidence concerns the gene SYK and allergic rhinitis.