CD79A and mature T-cell and NK-cell non-Hodgkin lymphoma: In particular, CD20 was detected in only two PTCL/NOS that were negative for CD79a, in keeping with previous observations of CD20 positivity in isolated PTCL/NOS, and CD79a aberrant expression in “specified” PTCL.27, 51–53 Co-expression of CD15 and CD30 was found in only 3/183 of cases that were able to be evaluated.