In ESCRT mutant clones, activation of the N pathway leads to transcription of the JAK/STAT ligand Upd, which acts non-autonomously on wild-type tissue to induce JAK/STAT signalling and promote neoplasia (Herz et al., 2006; Moberg et al., 2005; Vaccari and Bilder, 2005). The gene discussed is UROD; the disease is neoplasm.