BAMLET compounds are a novel class of protein-lipid complexes having promising anti-cancer activity. Originally discovered in milk, they comprise a protein and the active component oleic acid. We determined the structure of BAMLET by small angle X-ray (SAXS) and neutron (SANS) scattering[1-4]. SAXS revealed that the protein component has a novel, partially unfolded, and dramatically enlarged conformation with the protein volume located on the periphery of the complex. The lipid component was not revealed by SAXS because oleic acid has a similar X-ray scattering length density (SLD) to that of water. Employing the difference in the neutron SLDs of hydrogen and deuterium, we carried out solvent contrast variation SANS experiments of hydrogenated BAMLET in deuterated water buffers. SANS can "see" oleic acid because the neutron SLD of oleic acid (0.083 x 1010 cm-2) is very different to that of the heavy water solutions (4.991 and 6.376 x 1010 cm-2 for 80% and 100% D2O respectively). SANS revealed the size, shape, and disposition of the lipid component within the complex. The oleic acid of BAMLET forms a spherical droplet, incompletely encapsulated by the partially unfolded protein component. Our model provides insight into the anti-cancer mechanism of these compounds. Oleic acid is stably solubilised by the protein carrier when in an aqueous milieu. When the complex comes into contact with cancer cells, the oleic acid has higher affinity for the cell membrane and the oleic acid cargo is "released", resulting in membrane disruption. This model shows a slender protrusion of unfolded protein is available to interact with protrusions of other BAMLET molecules, providing a plausible explanation for how these compounds readily form aggregates. Our work is the first to determine the structure of this new type of protein-lipid structure, now called “liprotides”, and this structure has been confirmed and reproduced by others[5-6].