. E-cadherin is more often mutated
**Core Concept**
E-cadherin is a transmembrane glycoprotein crucial for cell-cell adhesion, particularly in epithelial tissues. Its mutations or downregulation lead to disrupted cell-cell interactions, contributing to tumor progression and metastasis in various cancers.
**Why the Correct Answer is Right**
The correct answer is associated with the fact that E-cadherin acts as a tumor suppressor by maintaining epithelial integrity. Mutations in the CDH1 gene encoding E-cadherin are commonly found in gastric and lobular breast cancers, leading to loss of cell adhesion and increased tumor aggressiveness. This is due to the disruption of the catenin-mediated signaling pathway, which is essential for maintaining epithelial polarity and preventing cancer cell invasion.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because E-cadherin mutations are not commonly associated with neurodegenerative disorders. While E-cadherin is expressed in various tissues, its primary role is in epithelial cell adhesion, not neuronal function or neurodegeneration.
* **Option B:** This option is incorrect because E-cadherin is not directly involved in the regulation of the cell cycle. Its primary function is in maintaining cell-cell adhesion, not in controlling cell proliferation or cycle progression.
* **Option C:** This option is incorrect because E-cadherin mutations are not typically associated with cardiovascular diseases. While E-cadherin is expressed in endothelial cells, its primary role is in epithelial cell adhesion, not in vascular function or cardiovascular disease.
**Clinical Pearl / High-Yield Fact**
E-cadherin mutations are a hallmark of lobular breast cancer, which often presents with a "pagetoid" pattern of cells infiltrating the lobules, leading to a characteristic "Indian file" appearance under histological examination.
**Correct Answer: D**