What is the role of integrins in the cell cycle?

Integrins play a significant role in cell adhesion and communication between cells and their extracellular matrix, which is crucial for many cellular processes including the cell cycle. In particular, integrins facilitate the attachment of cells to the extracellular matrix, which can provide the necessary signals for cells in a quiescent (inactive) state to re-enter the cell cycle. This engagement helps trigger pathways that lead to cellular proliferation, thereby promoting cell cycle progression.

When quiescent cells bind to the extracellular matrix through integrins, they receive mechanical and biochemical cues that signal to re-initiate cell division. This process is vital in tissue repair and regeneration, where cells may remain dormant until they are needed for growth or recovery. Hence, the correct answer directly highlights the role of integrins in aiding quiescent cells to transition back into active cell cycle phases.