Fluorescent images of carcinoma cells among cultured T lymphoblastoid leukemia cells stained with PE-labeled anti-cytokeratin monoclonal antibody (Fig. 9A) or APC-labeled anti-EpCAM monoclonal antibody (Fig. 9C) were obtained, and the merged image identified the doubly positive carcinoma cells (Fig. 9E). Here, EPCAM is linked to leukemia.