GFAP

Glial fibrillary acidic protein (GFAP) is an intermediate silk protein that only exists in astrocytes, with various functions such as maintaining structural stability, transmitting neural signals, and participating in cell division. GFAP is mainly used to diagnose cerebral glioma, and its positive expression suggests that the tumor originates from astrocytes. Moreover, the expression level of GFAP is positively correlated with the degree of tumor differentiation, indicating that GFAP gradually loses or mutates during tumor dedifferentiation, enabling cancer cells to acquire stronger invasion and metastasis abilities, so the patients with its high expression commonly have longer survival time and better prognosis. However, low GFAP level in astrocytoma will inhibit the production of CDK2, CDK4, and Cyclin D1, and up-regulate the expression of cell cycle inhibitors, thereby weakening the proliferation and differentiation of tumor cells. In addition, GFAP can assist in distinguishing between benign hyperplasia (+) and malignant lesion (-) of mammary ducts, and may also become a new biomarker for lung adenocarcinoma.