The present invention, in some embodiments thereof, relates to methods and devices for determining a disease state in a patient. In some embodiments, human serum albumin may be analyzed for associated molecules, wherein the associated molecules are related to a disease such as cancer. Certain aspects of the invention are generally directed to devices and methods for determining a disease state as a function of the three-dimensional structure of a blood protein, human serum albumin (HSA) or its complex with other ligands, e.g., due to binding to disease-specific ligands. HSA interacts with biomolecules associated with a disease presence, and liganded HSA may differentially partition between aqueous phases of a predetermined partitioning system, wherein the partitioning behavior differs between HSA from healthy individuals and HSA from people harboring the predetermined disease, such as breast cancer.