Cystatin F (CST7)

Cystatin F (CST7) is a glycosylated cysteine protease inhibitor primarily expressed in hematopoietic and immune cells, including microglia in the central nervous system[1][3][4]. It belongs to the type 2 cystatin family, and its unique ability to localize within endosomal and lysosomal compartments enables it to finely regulate the activity of cysteine proteases such as cathepsins, which are critical for antigen presentation, immune cell activation, and proteolytic processes[1][2]. Expression of CST7 is dynamically regulated during immune cell differentiation and activation and is implicated in modulating neuroinflammatory responses, especially in neurodegenerative diseases like Alzheimer’s disease, where it marks disease-associated microglia and is tightly associated with amyloid plaque pathology[2]. Beyond neurodegeneration, CST7 plays roles in tumor progression and immune modulation in cancer, and its expression level has been linked to clinical outcomes in pancreatic cancer and glioblastoma[1][3]. CST7 has potential utility as an early neuroinflammation biomarker and as a therapeutic target for diseases characterized by aberrant protease activity or immune dysregulation[1][2][3].

Other names

Cystatin-FCST7CMAPCystatin-7Cystatin-like metastasis-associated proteinLeukocystatincystatin 7cystatin-like metastasis-associated proteinleukocystatin

Endogenous inhibition of cysteine proteases such as cathepsin L and cathepsin C; Modulation of the endolysosomal and phagocytic pathways in microglia, influencing amyloid beta plaque pathology