Migration inhibitory factor (MIF) antibody-based SERS immunoassay can distinguish not only between pancreatic cancer patients and healthy controls, but also between metastatic and non-metastatic tumors, as well as tumor lymph node metastasis carmicheal used the unlabeled SERS technique in combination with a principal component differential function analysis algorithm to differentiate between exosomes derived from pancreatic cancer and normal pancreatic epithelial cells with 90% discriminatory accuracy. The gene discussed is MIF; the disease is pancreatic neoplasm.