ALK and neoplasm: These results were substantiated by soft agar assays demonstrating the ability of ALK-ST1, ALK-ST2, and ALK-ST3 to confer anchorage-independent growth (Fig. 3b) and by xenotransplantations in immunocompromised mice showing rapid induction of tumor growth by the ALK variants with higher efficiency than ALK-ATI (Fig. 3c).