TIGIT and rheumatoid arthritis: The TIGIT signaling pathway also affects immune responses through CD4+ and CD8+ T cells in cases of systemic lupus erythematosus, rheumatoid arthritis,21, 22 and human gastric cancer.23 A study on MC38 colon carcinoma revealed that 1B4 anti‐TIGIT antibody exerts deficient antitumor activity,16 which seems to contradict our conclusions.