However, the use of ubiquitous promoters carry the caveat of off-target effects, as seen in Tg(β-actin:K-RASG12D) fish where MPN was one of a spectrum of disease phenotypes, including rhabdomyosarcoma, intestinal hyperplasia, and malignant peripheral nerve sheath tumours [51]. The gene discussed is ACTB; the disease is myeloproliferative neoplasm.