These mouse DLBCLs showed expression of Irf4 and Foxp1, but were negative for Bcl6, CD10 and Gcet1 staining, consistent with a non-germinal centre origin, which is coincident with the type of DLBCL developed in case 1 (ref. 32; Fig. 3g). This evidence concerns the gene SERPINA9 and diffuse large B-cell lymphoma.