CDKN1A and neoplasm: However, p21 re-expression significantly inhibited the tumor weight and volume in the SH-NDRG1/p21 group compared to the ones in the SH-NDRG1 group: (483.1 ± 88.21 vs. 1292 ± 110.6 mg, p < 0.001 and 732.2 ± 283.9 vs. 3247 ± 353.2 mm3, p < 0.001).