CDKN1B and mantle cell lymphoma: In the model of CAM-DR in mantle cell lymphoma, we found that when malignant cells adhered to the bone marrow stromal cell line, HS-5, the p27Kip1 ubiquitination degradation significantly reduced the accumulation of p27Kip1 and the cell cycle arrest was triggered by an increase in p27Kip1 protein levels [29].