Then, in the previously published data by Abigail Benitez et al., as the belimumab study for systemic lupus erythematosus, a human BAFF inhibitor was used in a mouse model experiment, and they reported successful and favorable results: in vitro, it was confirmed that Foxp3+ Treg cells were decreased by adding recombinant BAFF, and in vivo, the increase in Treg cells was increased when belimumab was added (22). The gene discussed is FOXP3; the disease is systemic lupus erythematosus.