CDKN1A and B-cell chronic lymphocytic leukemia: In addition, lincRNA-p21 is significantly down-regulated in CLL patients, tested by the real-time PCR assay (forward primer sequence: 5′-GGGTGGCTCACTCTTCTGGC-3′ and reverse primer sequence: 5′-TGGCCTTGCCCGGGCTTGTC-3′ [5]), and the decreased plasma lincRNA-p21 level correlates with the CLL stage, which showed the clinical significance of lincRNA-p21 in CLL as a potential biomaker [34].