The role of SLC7A5 in T cell differentiation towards Th1, Th2, and Th17 has been previously described in vitro and in vivo in mouse models of viral infection (Hayashi et al, 2013; Sinclair et al, 2013), psoriasis (Cibrian et al, 2020), allergic diseases (Hayashi et al, 2020), and rheumatoid arthritis (Ogbechi et al, 2023). This evidence concerns the gene SLC7A5 and rheumatoid arthritis.