CPE and osteosarcoma: This is similar to another study where silencing of CPE expression caused decreased Cyclin D1 expression, cell cycle arrest and inhibition of proliferation of osteosarcoma cells.17 In BX-PC3 cells, it was suggested that CPE may exert its tumorigenic effect via NF-κB since CPE-regulated NF-κB expression, and NF-κB-siRNA inhibited invasion in these cells.