PRF1 and subcutaneous panniculitis-like T-cell lymphoma: In immunohistochemistry, the neoplastic cells in SPTCL express α/β cytotoxic T-cell phenotype, including CD8 (cluster of differentiation), TIA1 (T-cell intracellular antigen 1), granzyme B and perforin, but not CD56 and CD4 [1].