Podosomes are conical, actin-rich structures found as appendages on the outer surface of the plasma membrane of animal cells.

[8] Initial research suggested that the superstructure of podosomes were cylindrical, but new advances in bioimaging techniques have altered that perception and show the ring complex to display a polygonal form.

These finding were made possible through the application of Bayesian blinking and bleaching analytics to data gained from standard widefield microscopy using cells that expressed fluorescently tagged proteins specific to the podosome ring complex.

[15] The dendritic cells and macrophages of these patients’ immune systems do not manifest podosome formations and demonstrate defects in cellular movement within tissue microenvironments.

Patients who exhibit Frank–ter Haar syndrome are known to be mutant for the podosome specific protein Tks4 and demonstrate defects in neural crest cell migration.

[18] Initial formation of podosomes seems to be influenced by the structure and composition of the underlying substratum including the presence and distribution of specific ligands.

[22] During the maturation of osteoclast precursors, groups of podosomes form higher ordered ring structures which ultimately coalesce into a band about the cell periphery.

[23] Accumulation of F-actin, vinculin, paxillin, and α-actin within the podosomes of the coalescent band signals the development of a fully matured osteoclast.

[25] Inhibition of bone resorption through drug intervention results in the lack of the podosome band during early osteoclast differentiation and ultimate absence of a sealing zone.