Ribociclib is a potent cyclin-dependent kinase (CDK) inhibitor targeting cyclin D1/CDK4 and cyclin D3/CDK6 cell cycle pathway, with potential antineoplastic activity. LEE011 has been shown to reduce proliferation in 12 of 17 human neuroblastoma-derived cell lines by inducing cytostasis (mean IC50 = 306 nM in sensitive lines). MW: 434.54. Purity ≥98% by HPLC