TAPI-2 bounds to h-meprin with IC50 20 μM for h-meprin β subunit and 1.5 nM for h-meprin α subunit. Generally, h-meprin α is inhibited more strongly than the β subunit [1]. Without affecting ADAM17 expression, TAPI-2 dramatically decreases the protein levels of NICD and its downstream target HES-1 in both HCP-1 and HT29 cells. Moreover, treating cells with TAPI-2 significantly decreases the CSC phenotype by -50% in both CRC cell lines. The dose-dependent effects of TAPI-2 on the sphere formation and protein levels of NICD and HES-1 confirm that the concentration used (20 μM) is within the effective dose range of TAPI-2 (5–40 μM) [2].