This formulation has been validated in combination with systemic topotecan in two mouse models of retinoblastoma: MDMX mice (constitutively expressing MDMX, Chx10-Cre; Rblox/lox; p107-/-; MDMXTg background) and p53TKO mice (Chx10-Cre; Rblox/lox; p107-/-; p53lox/lox background). The gene discussed is MDM4; the disease is retinoblastoma.