CD19 and neoplasm: Fully in line with previous observations [15,22,23,24,26,42,43], CD45 and CD56, together with CD19 and both cell surface membrane and cytoplasmic CD3, enabled identification of tumor infiltrating leucocytes, including the major subsets of T, B, and NK cells and coexisting hematopoietic and/or non-hematopoietic tumor cells, in virtually all tumor infiltrated samples by histopathology/IHC, except for lymph node specimens from HL patients.