MEIS1 and colorectal carcinoma: Our results further indicate that the retino-sympathetic CRC, which includes the transcription factors RARA, SOX4, and MEIS1, as well as the shared members—HAND2, ISL1, and TBX2—is not capable of activating native MYCN enhancers included within its amplicon, so MYCN levels are rapidly down-regulated despite the high levels of amplification of the gene (Fig. 5E and fig.