This subgroup represents a distinct subset of ALK- ALCL because these cases (1) lack the expression of the genes associated with JAK-STAT3 signaling, (2) overexpress immunogenic cancer-testis antigen genes, (3) show marked DNA hypomethylation, (4) have a markedly reduced expression of PD-L1 and a high expression of CD58 and HLA class II [70] (Figure 9B). Here, STAT3 is linked to anaplastic large cell lymphoma.