these experiments indicate for epidermal cell spreading that mg++ is the important cation in tissue culture media , that under proper cation conditions epidermal cells do not need a specific spreading protein ( i.e . a protein that has been demonstrated to support cell spreading ) , that mn++ and mg++-induced spreading seem to represent different mechanisms , that fibroblastic and epidermal cells have different cation requirements for in vitro spreading , and that the crucial role cations play in cell spreading remains to be elucidated .
C0016030
fibroblastic
C0007634
cell