One study found that the combination of one antimicroRNA-21 ASOs (ASO-miR-21) and gemcitabine encapsulated by polyethylene glycol-polyethylenimine-magnetic iron oxide nanoparticles precoated with one target bullet fragment (scFvCD44v6) could downregulate oncogenic miR-21, thus leading to upregulation of tumor-suppressor genes programmed cell death protein 4 (PDCD4) and phosphatase and tensin homolog (PTEN) and the inhibition of aggressive invasion of PC cells in vitro. The gene discussed is PTEN; the disease is pachyonychia congenita.