Based on gene expression profiling [23,24], Amador and colleagues recently assessed Th1 (Tbet and CXCR3) and Th2 (GATA3 and CCR4) protein expression using the IHC algorithm in cases of nodal and extranodal peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS). The gene discussed is TBX21; the disease is peripheral T-cell lymphoma, not otherwise specified.