“…Proteases belonging to the non-amelogenin group are represented by matrix metalloproteinase-20 (MMP-20), also called enamelysin, and kallikrein 4 (KLK-4). MMP-20 is secreted during amelogenesis with other enamel proteins [ 25 , [29] , [30] , [31] ]. MMP-20 as a tooth-specific protease is expressed in ameloblasts in their secretory and early maturation stages [ 29 , 32 , 33 ].…”