TSPAN7, a quadruple transmembrane glycoprotein encoded by the tspan7 gene located on the X chromosome, is highly expressed in brain tissue and pancreas. TSPAN7 has been found to form Tspan-enriched microdomains or TSPAN networks in cell membranes, which are involved in the regulation of biological processes such as intra- and extracellular information and material exchange, cytoskeletal dynamics, cell motility and cell morphology. In tumor cells, TSPAN7 acts as a double-edged sword with the ability to either promote or suppress tumors through its altered expression in tumor cells. In immune cells, TSPAN7 can act as a positive regulator of actin nucleation and stabilization,and is involved in the morphogenesis of dendritic cells. In neuronal cells, TSPAN7 is involved in synaptic transmission and neuronal morphogenesis In pancreatic islet cells, TSPAN7 controls the entry of calcium (Ca²⁺) into pancreatic β-cells by regulating voltage-dependent Ca²⁺ channels, thus affecting insulin secretion. TSPAN7 is also involved in the development of many diseases such as tumors, psychiatric disorders, and type 1 diabetes. This article reviews the mechanisms of TSPAN7 in various diseases, with a view to providing new ideas for animal model development, disease diagnosis, and drug intervention.