FOXP3 and rheumatoid arthritis: Beyond transplantation and GvHD, several other autologous CAR- and TCR-redirected FOXP3+ Treg cell therapies are being developed for various autoimmune diseases, including multiple sclerosis (NCT06566261), SLE and lupus nephritis (175, 176), rheumatoid arthritis (NCT06201416), and hidradenitis suppurativa (NCT06361836).