CD5 and extranodal nasal NK/T cell lymphoma: In addition, NKTCL and ANKCL tumor cellsnearly always express CD2 and less often CD7 and CD8, but not CD4 and CD5.From the markers usually used to identify NK-cells, CD56 is the mostfrequently positive, whereas CD16 expression is variable, and CD57 is almostnever found.