UC2288 is a novel, cell-permeable, and orally active p21 attenuator (relatively selective activity for p21), which is synthesized based Sorafenib (HY-10201). UC2288 decreases p21 mRNA expression independently of p53, and attenuates p21 protein levels with minimal effect on p21 protein stability. UC2288 has no inhibition of VEGFR2 and Raf kinases even at 10 μM.