About flow cytometry, CD20 and CD19 characterize all B-cell lymphomas, while CD3, CD4, and CD8 are characteristic of T-cell histotypes; CD11c is typical for HCL, CD30 is detected in some T-cell lymphomas, but, differently from the chronic lymphocytic leukemia (CLL) (59, 60) or multiple myeloma (61, 62), where specific antibodies combinations and guidelines for MRD detection are available, in NHLs the role of flow cytometry in the MRD scenario is not well-established, perhaps because there is not a strict correlation between flow cytometry and microscope or molecular biology. Here, CD4 is linked to B-cell chronic lymphocytic leukemia.