STAT3 and aneurysmal bone cyst: All ABC‐DLBCL, but none of the investigated GCB‐DLBCL, cell lines express gp130 at least at low levels; the expression of gp130 appears to be a prerequisite for the ability of the cell lines to activate STAT3 upon exposure to IL‐6, as none of the GCB cell lines showed STAT3 phosphorylation upon IL‐6 treatment, despite expressing copious amounts of STAT3 itself.