MKI67 and marginal zone lymphoma: Although a correlation between Ki-67 PI evaluation and the grade of NH nBCLs in FNAB samples was found in some studies, mainly for lymphoma subtypes such as DLBCL, FL, MCL, and marginal-zone lymphoma (MZL) [20,21,22,23], the percentage of Ki-67-positive cells showed a substantial overlap between aggressive and indolent lymphomas.