SPP1 and lung cancer: In accordance with our findings in vivo, tumour EndMT was prominently seen in lung cancer tissues of patients who received irradiation, with large populations of OPN+CD44v6+ CSCs and SDF-1+CD206+ macrophages, even though the patients had received fractioned radiotherapy, indicating that radiation-induced CD44v6+ tumour cells and SDF-1+ M2 macrophages might be targeted for overcoming tumour radioresistance.