Phenotypic switching is switching between multiple cellular morphologies. David R. Soll described two such systems: the first high frequency switching system between several morphological stages and a second high frequency switching system between opaque and white cells. The latter is an epigenetic switching system[1][2]
Phenotypic switching in Candida albicans is often used to refer to the epigenetic white-to-opaque switching system. C. albicans needs this switch for sexual mating.[3]
Next to the two above mentioned switching systems many other switching systems are known in C. albicans.[4]
A second example occurs in melanoma, where malignantly transformed pigment cells switch back-and-forth between phenotypes of proliferation and invasion in response to changing microenvironments, driving metastatic progression.[5][6][7]