During the preparation of this manuscript, the same sample was inadvertently included for the +/L1002P and +/– images in Figure 2E. The authors were able to use the original samples to prepare a corrected version. The correct figure is below. The description in Methods for this panel has also been corrected, as below: To assess the mitotic index of spontaneous lymphatic tumors, mitotic cells were visualized by IF labelling of at least 1 paraffin section for pHH3 (EMD Millipore, catalog 06-570), as described (6, 46). The online version of the article has been updated with the corrected information. The authors regret the errors.