Albumin-bound/conjugated chemotherapies such as nab-paclitaxel (Abraxane) are a class of chemotherapies that have shown improvements over conventional chemotherapy in certain tumor types, resulting in reduced toxicity and/or increased efficacy. The improved targeting to tumor cells is thought to be in part due to an enhanced permeability and retention effect within tumors, but no useful molecular biomarkers exist to predict efficacy to this class of drugs. Caveolae are flask-shaped invaginations of the plasma membrane that appear important for albumin uptake, and caveolin-1 is the protein required for caveolae formation. Using immunofluorescence, it was found that the degree of caveolin-1 expression dictates uptake of nab-paclitaxel, as visualized by immunofluorescence for albumin (green) in DAPI-stained (blue) tumor cells. For details, see article by Chatterjee and colleagues on page 5925.