We show here that SCLC drug development should take into account CXCR4/STAT3 linkage to target more specifically the malignant cells; although JAK2/STAT3 seems to have a dominant function in anchorage-independent cell proliferation, it has a minor function in adhesive processes of SCLC cells where CXCR4 antagonists should prove more efficient. Here, JAK2 is linked to small cell lung carcinoma.