RTKN2 and systemic lupus erythematosus: To be specific, PBX1 upholds the equilibrium and constancy of T reg cells via the advancement of the cell cycle by targeting rhotekin 2 (Rtkn2), thus impeding the proliferation of inflammatory T cells that, if left unchecked, could intensify the progression of lupus in the hosts (Gu et al., 2023; Choi et al., 2024).