Fig. 10. Model for Cad99C function. Cad99C is present on follicle cell microvilli and, through its extracellular cadherin repeats, could establish molecular links to the extracellular matrix, to Cad99C or to a different heterophilic binding partner on a neighboring microvillus, or to a protein located on the oocyte surface. These molecular links could stabilize or promote the assembly of microvilli by providing physical adhesion of the microvilli to a target and/or signaling to the cytoskeleton.