Esculetin was found to inhibit cell growth and cell cycle progression by inducing G1 phase retention in human leukemia HL-60 cells in the study by Wang et al. In this study, it has been shown that esculetin provides a significant increase in the level of hypophosphorylated retinoblastoma protein (pRb) and a decrease in CDK4 level, and also significantly upregulation of p27 and downregulation of cyclin D1. This evidence concerns the gene RB1 and leukemia.