CRISPR roadblocks: Scientists identify genes blocking gene therapy success

Like a delivery driver navigating crowded city streets, a gene-therapy-toting lipid nanoparticle faces a gauntlet of potential detours on its journey toward a cell's nucleus. First, there's entering the cell's plasma membrane; then navigating around organelles like the Golgi apparatus, mitochondria and endoplasmic reticulum—all destinations that can errantly absorb the particle's payload, rendering it ineffective at best or harmful at worst. And that's all before the particle even enters the nucleus and successfully makes a genetic change.