Cell polarity arises primarily through the localization of specific proteins to specific areas of the cell membrane. This localization requires both the recruitment of cytoplasmic proteins to the cell membrane and polarized vesicle transport along cytoskeletal filaments to deliver transmembrane proteins from the golgi apparatus . Many of the molecules responsible for regulating cell polarity are conserved across cell types and throughout metazoan species. Examples include the PAR complex ( Cdc42 , PAR3 /ASIP, PAR6, atypical protein kinase C ),   Crumbs complex (Crb, PALS, PATJ, Lin7), and Scribble complex (Scrib, Dlg, Lgl).  These polarity complexes are localized at the cytoplasmic side of the cell membrane, asymmetrically within cells. For example, in epithelial cells the PAR and Crumbs complexes are localized along the apical membrane and the Scribble complex along the lateral membrane.  Together with a group of signaling molecules called Rho GTPases , these polarity complexes can regulate vesicle transport and also control the localization of cytoplasmic proteins primarily by regulating the phosphorylation of phospholipids called phosphoinositides . Phosphoinositides serve as docking sites for proteins at the cell membrane, and their state of phosphorylation determines which proteins can bind. 
Cell fate specification or cell differentiation is a process where undifferentiated cells can become a more specialized cell type. Wnt signaling induces differentiation of pluripotent stem cells into mesoderm and endoderm progenitor cells .  These progenitor cells further differentiate into cell types such as endothelial, cardiac and vascular smooth muscle lineages.  Wnt signaling induces blood formation from stem cells. Specifically, Wnt3 leads to mesoderm committed cells with hematopoietic potential.  Wnt1 antagonizes neural differentiation and is a major factor in self-renewal of neural stem cells. This allows for regeneration of nervous system cells, which is further evidence of a role in promoting neural stem cell proliferation.  Wnt signaling is involved in germ cell determination, gut tissue specification, hair follicle development, lung tissue development, trunk neural crest cell differentiation, nephron development, ovary development and sex determination .  Wnt signaling also antagonizes heart formation, and Wnt inhibition was shown to be a critical inducer of heart tissue during development    , and small molecule Wnt inhibitors are routinely used to produce cardiomyocytes from pluripotent stem cells   .
According to researchers at Tufts University, the two phenomena – lowered polarization and tumor development – are connected by a straightforward chain of events. Cells become polarized when there is an imbalance of the positive and negative ions that flow in and out of cells through channels in cell membranes.