GFAP and neoplasm: At approximately 18 days post-transplant (18 dpt, or 20 dpf), we screened for mScarlet+ fluorescence and visualized her4.1+/gfap+ tumor cell outgrowth in 16–25% of transplanted hosts (n=3 independent screens, Figure 1E and F), supporting oncogenic transformation and malignant growth in vivo of p53EPS cells.