This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The primary aims of this study are to define the maximum tolerated dose (MTD), toxicity profile, and pharmacokinetics of intravenous emulsion fenretinide when given continuously for five days, every three weeks, in pediatric patients with recurrent and/or resistant acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), and non-Hodgkins Lymphoma (NHL).