Nutlin-3 is an activator of p53 that functions by inhibiting the interaction of p53 with MDM2, a negative regulator of p53 activity. Caylin-2 is a nutlin-3 analog in which trifluoromethyl groups have been substituted for chlorine on the 2 phenyl rings. At high concentrations, caylin-2 inhibits the growth of HCT116 cells with an IC50 of approximately 8 μM, making it about 10-fold less potent than nutlin-3. Interestingly, at concentrations between 5-100 nM, caylin-2 promotes the growth of HCT116 cells approximately 40% compared to untreated cells. The mechanism of the growth promoting properties of caylin-2 have not yet been elucidated.