A model of tumor growth that interacts with the immune system is introduced. This model considers three main compartments: proliferative tumor cells, quescent tumor cells, and the immune system. The proliferating tumor cells are in turn divided into two others sub-compartments (tumor cells during interphase and mitosis) to take into account the cell cycle. We show that the system exhibits a tumor free fixed point, and the conditions fot its stability are stablished. Conditions for the existence and stability of coexisting fixed points are also provided. Numerical simulations with and without quescent are shown, as wll as the sensibility analysis of the model's parameters.