CD19 and neoplasm: Such antibody panels aim at the identification of the tissue origin of the tumor and include reagents for myogenic (e.g., nuMyoD1, numyogenin, desmin, myoglobin), neural/neural crest (e.g., NSE, NB-84, TrkA, NFTP, synaptophysin, CD56, CD99), and germ cell tissues (e.g., alpha fetoprotein, PLAP, cytokeratin), in addition to mesenchymal (e.g., vimentin, smooth muscle actin) and hematopoietic cell-associated markers (e.g., CD45, CD3, CD19, CD20, myeloperoxidase (MPO)) [2,5,6].