CCND1 and glioblastoma: In a proof-of-concept experiment, Gu et al. designed a decoy oligodeoxynucleotide comprised of a STAT3-specific DNA cis-element and transfected it into human GBM cells U251 and A172, finding specific blockade of STAT3 activation with subsequent cell-cycle arrest and apoptosis mediated by decreases in mRNA levels of c-Myc, cyclin D1, and Bcl-xL [71].