ZIC4 and brain neoplasm: The rad21;RAS brain tumor model was generated by first crossing the zic driver line (Et(zic4:GAL4TA4,UAS:mCherry)hmz5) with rad21ahi2529Tg/+ fish, and named zic:rad21a+/−, followed by the injection of the human UAS:eGFP-HRASv12 oncogene into one-cell-stage embryos (Figure 1A), or by crossing zic:rad21a+/− fish with the tg(UAS:eGFP-HRASV12G)io006 line to generate fish with brain tumors and rad21a haploinsufficiency.