A rapid, ultrasensitive, and inexpensive nanoplasmon-enhanced scattering (nPES) assay that directly quantifies tumor-derived EVs from as little as 1 μL of plasma was used by Liang et al. to identify a possible PC EV biomarker, ephrin type-A receptor 2 (EphA2). The gene discussed is EPHA2; the disease is neoplasm.