According to a study from Italy, patients who expressed CXCR4 in their SS cell nucleus, had a poor prognosis when receiving adjuvant chemotherapy. Patients who expressed IGF-1R in their SS cell nucleus and did not have chemotherapy, also had a poor prognosis. In other words, patients who express IGF-1R should get chemotherapy while patients who express CXCR4 are resistant to chemo. The study abstract can be found here: