  Cell adhesion, a fundamental process of cell biology is involved in the
embryo development and in numerous pathologies especially those related to
cancers. We constrained cells to adhere on extracellular matrix proteins
patterned in a micro lattices. The actin cytoskeleton is particularly sensitive
to this constraint and reproducibly self organizes in simple geometrical
patterns. Such highly organized cells are functional and proliferate. We
performed statistical analysis of spread cells morphologies and discuss the
existence of a fundamental lengthscale associated with active processes
required for spreading.
