MAPK9 and cancer: For example, targeted depletion of either JNK1 or JNK2 with antisense oligonucleotides caused cell proliferation inhibition associated with S-phase arrest and p53-independent induction of the cyclin-dependent kinase (Cdk) inhibitor p21 as well as subsequent decreases in both Cdk1 and Cdk2 kinase activity in cancer cells (Potapova et al., 2000).