PDCD1 and inflammatory bowel disease: In contrast, mucosal studies have consistently reported significantly higher PD-1/PD-L1 expression in UC, underscoring compartment-specific checkpoint activation.41,42 Disease-specific nuances may influence the magnitude of response; however, as our approach directly targets CD4+ T-cell dysregulation, which is a shared hallmark of CD and UC, it is expected to confer therapeutic benefits across IBD.