CD274 and rheumatoid arthritis: Although some studies have proposed that significant improvements were observed in the CIA models treated with the strategy of overexpressing PDL1, the PDL1-PD1 signaling axis has recently been discovered to facilitate the humoral immune response by maintaining the survival and activation of B cells, which is the most intractable problem in RA (Ogishi et al. 2024; Wood et al. 2024; Wang, et al. 2023).