Given previous studies where expression of the C11orf95-RELA type 1 fusion (RELAFUS1) was sufficient to induce formation of ependymoma-like brain tumors in mice [17, 21], we generated a pTomo-RELAFUS1-HA (containing a C-terminal human influenza hemagglutinin [HA] tag) lentiviral vector which can induce the exogenous gene expression in a cell-type-specific manner using the Cre-loxP system (Additional file 6: Fig. S1A and B) [12]. The gene discussed is ZFTA; the disease is brain neoplasm.