While STAT3 activation is induced by ALK fusion proteins in ALK-positive ALCL, it is induced by somatic mutations of STAT3 and JAK1 in 20% of ALK-negative anaplastic large cell lymphomas and 5% of primary cutaneous ALCL, whereas mutations in these genes have not been reported for CD30+ PTCL [41,49,50]. Here, JAK1 is linked to anaplastic large cell lymphoma.