FOS and anaplastic large cell lymphoma: In NPM-ALK-positive (ALK+) ALCL, it has been shown that most changes leading to cell transformation are induced by transcription factors (TFs) such as STAT3/5, CEBPB, and AP1 (Leventaki et al., 2007; Mathas et al., 2002; Piva et al., 2006; Rassidakis et al., 2005; Turner et al., 2007; Zamo et al., 2002).