Cooperative signaling between growth factor receptor tyrosine kinases, integrins, and the actin cytoskeleton is required for activation of the G1-phase cyclin-dependent kinases and progression through G1-phase. Increasing evidence suggests that there is cell type specificity in these cooperative interactions and that the compliance of the underlying substratum can strongly affect adhesion-dependent signaling to the cell cycle. This chapter reviews our current methods for studying how cell type specificity and changes in substratum compliance can contribute to G1-phase cell cycle control. We also describe several of our current analytical procedures.