employed a PNA‐based MSNP delivery system to silence B‐cell lymphoma 2 (Bcl‐2) protein expression in vitro.[101] The antisense PNA, covalently linked to MSNP through a disulfide bond, entered the HeLa cells via endocytosis and selectively reached cancer cells through a redox‐controlled release mechanism, inducing an efficient silencing of Bcl‐2 protein expression. Here, BCL2 is linked to cancer.