Expression of Lef1 in primary T-cell lymphomas. (A) Northern blot of RNA from primary lymphomas isolated from thymus or lymph nodes (LNs) of E2A^−/− (A, and nos. 24, 1, 39) or E2A^−/−Rag2^−/− (nos. 53, 35, 52) mice compared with the E2A^−/− lymphoma line 1.F9 or the p53^−/− lymphoma line 16610D9. Probes specific for Lef1, Tcf1, and actin mRNA were used as indicated. Vertical lines have been inserted to indicate where a gel was cut. All lanes are from the same gel. (B) Western blot of primary lymphoma lines using Lef1 specific antibody (top panel). The same blot was subsequently probed with anti-Notch1 reactive with ICN1. ICN1 is a unique size in each lymphoma due to mutations resulting in truncation within the PEST domain. Vertical lines have been inserted to indicate where a gel was cut. All lanes are from the same gel.