TFF1 and carcinoma: By measuring the levels of miR‐330‐5p and miR‐326 in clinical tissues, it was verified that only miR‐326 expression in breast cancer tissues was dramatically lower than in healthy and para‐carcinoma samples, and the negative association between miR‐326 and circ‐TFF1 was also demonstrated by Pearson's correlation analysis (Figure 5C).