The present study is the first to demonstrate that JQ1 reduces the viability of ovarian cancer cells and primary cultured ovarian cancer cells by inducing apoptosis (through the downregulation of MCL-1 and BCL-2), cell cycle arrest (through upregulation of p21 and p27, downregulation of cyclin D1, CDK4 and CDK6), and by inhibiting ovarian cell migration and metabolism. This evidence concerns the gene CDK4 and ovarian cancer.