While cdkn2a/b gene inactivation accelerated development of Malignant Peripheral Nerve Sheath Tumors (MPNSTs) by TALEN injection in tp53 e7/e7 mutation background, TALEN-mediated somatic inactivation of rb1, which is a potential downstream target of CDKN2A/B, induced distinct brain tumors in the tp53 e7/e7 mutation background. Here, RB1 is linked to brain neoplasm.