CDH1 and cancer: Multiple investigations have identified the H. pylori HtrA protein as an E-cadherin-targeting protease that actively catalyzes the breakdown of the extracellular domain of E-cadherin, thereby breaking cell–cell adhesion and promoting the development of cancer (Hoy et al., 2012; Schmidt et al., 2016a,b; Tegtmeyer et al., 2016).