PPIG and Autoimmunity: The rationales behind FDA's inadequate conclusions include the lack of an established exposure–response relationship between IL‐6 and CYP suppression as well as the time course of the interaction, the focus on evaluating the effect of IL‐6 on CYP substrates but no other cytokines (such as IL‐2, IL‐6, IL‐10, TNF‐α, IFN‐γ, etc.), and the use of data in patients with chronic autoimmune and inflammatory diseases to validate PBPK model for IL‐6.5, 6, 7, 8