Consistent with the results from the tumor formation assay, idasanutlin treatment was only effective in reducing the overall percentage of tumor cells in fish injected with GATA3-silenced cells (purple vs DMSO-treated in blue) but not in fish injected with control (yellow vs DMSO-treated in black, Fig. 3d), indicating that GATA3 expression level modulates sensitivity to MDM2 inhibition in vivo. The gene discussed is MDM2; the disease is neoplasm.