1) T cell responses against antigens expressed in autochthonous lung tumors can delay malignant tumor progression. However, these T cell responses are not sustained over time. 2) Vaccination against antigens expressed in autochthonous lung tumors promotes an initial protective T cell response but also drives tumor antigen loss, allowing tumor escape. 3) Transplantation of lung tumor cell lines or vaccination against antigens in transplantable lung tumor models results in rejection of tumor or selection of antigen-loss variants, demonstrating immune editing.