Plasma cell and NPM-ALK tumors.

(A) Southern blot analysis of plasma cell tumors showing rearranged pattern of the immunoglobulin gene. Germline liver DNA was used as control. (B) Constitutive expression of Stat3 in NPM-ALK tumor cells. Total cell extracts from NPM-ALK⁺ cell lines (lanes 1,2) and from fresh tumors were immunoblotted with the indicated antibodies. Thymic tumor derived from Δcul1 transgenic mice served as controls.