Interestingly, we observed that Hdac1 and Hdac2 are not deleted in tumors arising in 4-OHT treated transplanted mice (Supplementary Figure 5), suggesting that the delayed tumor growth observed represents cells that have escaped deletion of Hdac1 and Hdac2. From these findings we conclude that the partial effect we observed after 4-OHT treatment of transplanted recipient mice (Fig. 4) can be explained by incomplete elimination of Hdac1 and Hdac2 using the tamoxifen inducible CreERT system. This evidence concerns the gene HDAC1 and neoplasm.