Rac1 is a pleiotropic regulator of many cellular processes, including the cell cycle, cell-cell adhesion, motility (through the actin network), and of epithelial differentiation (proposed to be necessary for maintaining epidermal stem cells).

In addition, this group of tumors reflects a continuum in histologic heterogeneity as well as epithelial and mesenchymal differentiation.

During the process of epithelial differentiation, cells become cornified as keratin protein is incorporated into longer keratin intermediate filaments.

Astroblastoma: Immunohistochemical and ultrastructural study of distinctive epithelial and probable tanycytic differentiation.

Histone deacetylase inhibitors such as sodium butyrate strongly up-regulate cingulin expression in some cultured cells, indicating that cingulin is a marker of epithelial differentiation.

Significantly, because decreased levels of ART-27 are consistently found in prostate cancer cells, it likely plays a role in promoting epithelial differentiation via suppression of proliferative pathways.

Multiple mechanisms can suppress miR-203 expression in malignancies: Wellner et al. show that ZEB1 represses expression of miR-203 together with the miR-200-family whose members are strong inducers of epithelial differentiation.

Cholangiocarcinoma is a medical term denoting a form of cancer that is composed of mutated epithelial cells (or cells showing characteristics of epithelial differentiation) that originate in the bile ducts which drain bile from the liver into the small intestine.

Small cells that reflect neither epithelial nor stromal differentiation.

In the lung and liver, common sites of metastatic tumor, it was most likely to be confused with carcinoma (tumor with epithelial differentiation), a far more common type of tumor.