Drosophila melanogaster Cad99C, the orthologue of human Usher cadherin PCDH15, regulates the length of microvilli.

Actin-based protrusions can form prominent structures on the apical surface of epithelial cells, such as microvilli. Several cytoplasmic factors have been identified that control the dynamics of actin filaments in microvilli. However, it remains unclear whether the plasma membrane participates actively in microvillus formation.