CCND1 and clear cell renal carcinoma: So far, the data on L1CAM expression in renal clear cell carcinoma were contradictory; studies have shown that cell adhesion, metastasis, and invasion abilities were significantly increased with the upregulation of L1CAM expression in KIRC, and in turn, the downregulation of LICAM expression decreased the proliferation of renal cancer cell and reduced the expression of cyclin D1 [28, 29].