MCL diagnosis is based on standard histopathological examination complemented essentially by immunohistochemical staining for CD20, CD5, cyclin D1 and Ki67 and frequently supplemented by broad immunohistochemical panels including SOX11, TP53, p16, C-MYC, molecular analysis of 11q13 translocation and inclusion of clinical parameters, such as lactate dehydrogenase levels and white blood cell counts2,3. Here, MKI67 is linked to mantle cell lymphoma.