LIN28B and atypical teratoid rhabdoid tumor: The short duration until tumor formation, the development of multiple primary tumors per mouse and the low number of copy number changes and mutations found in the tumors indicate that transgenic Lin28b overexpression results in a rapidly developing highly penetrant murine tumor model requiring little if any additional genomic alterations, in keeping with the situation in human atypical teratoid rhabdoid tumors [37].