Engineering**: -The hierarchical regulatory networks of miRNAs and phasiRNAs offer new opportunities for metabolic engineering. The authors suggest that miRNA sponges, competing endogenous RNAs (ceRNAs), and CRISPR/Cas9 genome editing techniques could be employed to knock out or inhibit miR-NAs/phasiRNAs, thereby releasing the full expression potential of paclitaxel biosynthesis genes. This could significantly enhance the production of paclitaxel in engineered *Taxus* cell lines.