After establishment of the tumors generated by NOTCH1+ and NOTCH1− cells, the primary recipient cerebellar tumors were harvested and the NOTCH1+ and NOTCH1− cells were resorted from these primary tumors and re-transplanted into the cerebella of secondary recipients (second passage in vivo) (Fig. 3c–f). The gene discussed is NOTCH1; the disease is cerebellar neoplasm.