IWR-1 is a tankyrase inhibitor which inhibits Wnt/β-catenin signaling pathway. IC50 & Target: IC50: 180 nM (Wnt) In Vitro: Both IWR-1 and XAV939 act as reversible Wnt pathway inhibitors and exhibit similar pharmacological effects in vitro. IWR-1 exerts its effect via interaction with Axin, while XAV939 binds TNKS directly^[1]. IWR-1 (10 μM) induces stabilization of β-catenin disruption complex. IWR-1 (10 μM) is added to the medium together with MIF, the size of cell colonies is extremely decreased, and that indicates the promoting effect of MIF on NSPC proliferation is inhibited by IWR-1 in any MIF concentration group. 2, 5 and 10 μM of IWR-1 significantly inhibits the proliferation of NSPC dose-dependently. IWR-1 inhibites the promoting effect of MIF on NSPC differentiation to neuron lineage^[2]. IWR-1 treatment in the presence of maximal stimulatory dose of FSH (0.5 ng/mL) results in a dose dependent inhibition of the stimulatory effect of FSH with > 75% inhibition observed at the maximal inhibitory dose of IWR-1 (1 µM). IWR-1 treatment partially reverses the FSH-induced inhibition of granulosa cell CARTPT mRNA expression^[3].