many of the key polarity proteins are well conserved, different mechanisms exist to establish cell polarity in different cell types. Here, two main classes can be distinguished: (1) cells that are able to polarize spontaneously, and (2) cells that establish polarity based on intrinsic or environmental cues.

Spontaneous symmetry breaking can be explained by amplification of stochastic fluctuations of molecules due to non-linear chemical kinetics. The mathematical basis for this biological phenomenon was established by Alan Turing