CCNA2 and Leber congenital amaurosis: Immunoblotting results revealed that following LCA treatment, the levels of cyclin A, cyclin B1, and Wee1 were reduced, and the effect was concentration dependent, while the expression of cyclin-dependent kinase (Cdk) 2 and cell division cycle (Cdc) 2 was relatively maintained at the level of the control group (Figure 3A).