CCNB1 and breast carcinoma: Supporting the roles of ERLIN2 in stabilizing Cyclin B1 protein and enhancing Cyclin B1/Cdk1 function in breast cancer cells, levels of Cyclin B1 and phosphorylated Cdc27 were increased in ERLIN2-expressing MCF10A cells but decreased in ERLIN2-knockdown SUM225 cells, compared with their controls (Figure 6a).