TYK2 and systemic lupus erythematosus: By organizing available data across six prespecified overlap subgroups and incorporating contextual mechanistic insights—including TYK2 inhibition [35,36,37], ustekinumab SLE trials [33], and IL-17 inhibitor-associated CLE [26,27,28,29,30,31]—we aim to propose a pragmatic, phenotype- and pathway-guided framework for systemic treatment selection in this complex overlap population.