Increased function of circNAB1 was associated with decreased production of cytokines such as TNF‐α, IL‐1β, IL‐2, IL‐4, IL‐10, and IL‐17, cytokines that modulated tissue fibrosis.[32, 33] Our findings suggest the anti‐fibrotic activities of circNAB1 may confer it as a potential therapeutic target for AF‐associated cardiac remodeling through regulating cytokine syntheses. Here, IL4 is linked to atrial fibrillation.