MSR1 and neoplasm: In this study, our observations suggest that tumor cells and CD204+ macrophages may cooperatively contribute to a more aggressive behavior of lung adenocarcinoma and that targeting CD204+ TAMs may be an adjuvant therapy to the conventional anticancer regimens for lung adenocarcinoma, although surgery remains the standard treatment for the patients in stage I. In addition, the diameter of the tumors included in the current study were all ≤2 cm.