Amsilarotene
Amsilarotene is a retinobenzoic acid with potential antineoplastic activity. Amsilarotene inhibits retinoblastoma-gene product (RB) phosphorylation and increases the presence of 2 cyclin-dependent kinase (CDK) inhibitors, resulting in cell cycle arrest.  This agent also causes a cytotoxic decline in cyclin A and thymidylate synthase expression.