Furthermore, the qRT–PCR results show that the miR-7a-5p expression significantly decreased in samples of the SN from mouse models of PD (Fig. 4C) and the circ-Pank1 knockdown increased the expression level of miR-7a-5p in MN9D cells treated with rotenone (Fig. 4D). Here, PANK1 is linked to Parkinson disease.