The catalytic function encoded in oligonucleotides (DNAzymes) was employed for gene silencing and cancer therapy through DNAzyme/particle conjugates.[138] This is exemplified in Figure5A with the cancer cell‐dictated evolution of a Mn2+‐dependent DNAzyme that silences the mRNA associated with the human early growth response‐1 (EGR‐1) protein, thereby inducing apoptosis of the cancer cells. The gene discussed is EGR1; the disease is cancer.